Site Conservation 2014


Site Conservation has always been a high priority at Gordion, and it will continue to be one of the most important activities during the coming field seasons. A new Conservation and Management Plan for the Gordion Citadel began in 2007, under the supervision of Prof. Frank Matero and the Architectural Conservation Laboratory of Penn’s School of Design (ACL). The current project is based on an integrated and phased program of academic research, site conservation, and training.

The primary focus of architectural conservation works during the 2014 field season were the Terrace Building Complex, the Early Phrygian Gate, the Visitor Circuit, and the pebble mosaic in display at the Gordion Museum.

The Terrace Building (9th century B.C.), located on the southwest side of the eastern citadel mound, is composed of eight large rooms that functioned as workshops for textile production and food processing. It has been excavated for its entire length of over 100 meters, thus making it one of the largest buildings of ancient Anatolia. The Terrace Building is among the most prominent ruins of the Early Phrygian citadel, and is visible from almost every corner of the visitors’ circuit. Conservation in 2014 continued with the structural stabilization of the walls inside Building 5 (TB5) and documentation of the construction and conditions of the wall in Building 7 (TB7).

The other significant conservation project that started in 2014 is the stabilization of the Early Phrygian Gate. This is the best-preserved city gate in Iron Age Asia Minor and it has remained intact for nearly three millennia. A significant bulge has recently developed in the limestone masonry of the South Court, however, and it is increasing each year, thereby jeopardizing its stability. In 2014 scaffolding to provide access for stabilization works on the north and east walls of the gate’s South Court was installed. Works included ground leveling of the central ramp, construction of a timber mat foundation for the heavy-duty scaffolding along the north wall, and access scaffolding.

New galvanized cable railings and stone steps have been installed over the last three years to improve and extend the Visitor Circuit in the citadel as requested by the local authorities. In 2014, stabilization of the scarp slopes and replacement of the barbed wire fence with new galvanized railing were completed along the area between visitor’s information panel 4 and 6 on the north side of the Citadel.

In 2013, a selected panel from Megaron 2 pebble mosaic currently housed in the Gordion Museum was temporarily faced, then lifted and stored at the Gordion Museum. Discovered in the 1950s, the Megaron 2 pebble mosaic floor is the earliest known mosaic to have been found (9th century B.C.) and features elaborate polychromatic geometric designs. Shortly after discovery the pavement was cut into sections for lifting and transported to the Gordion Museum. In 2014, following on three years of research and planning, conservation treatment started on the lifted panel by removing the old reinforced concrete backing using a custom-made grinding system.

Terrace Building Complex

The Terrace Building Complex is an industrial zone of Early Phrygian date (9th century B.C.) on the southwest side of the eastern citadel mound. In 2009 the site program explored new methods of conservation and preservation of the Terrace Building Complex to maximize the archaeological value of the existing walls and floors with no or limited rebuilding and to improve legibility with no or limited reburial. A pilot conservation program of the walls in TB2 was established according to objectives and intervention strategies to minimize visual impact, reduce maintenance requirements and limit the need for future interventions. These resulted in the development of a set of guidelines for works at the TB Complex.

The focus of masonry conservation works during the field seasons of 2014 was Terrace Building 5. All wall treatments were conducted following guidelines established in 2009. Works were carried out under the direction of Angelo Lanza assisted by Giuseppe Bomba and a team of trained local laborers. Intervention was limited to five weeks (June 18 – July 23) because the group was engaged in setting up conservation works at the museum at the beginning of the season and in masonry works at the gate after scaffolding/shoring installation.

Site photography and survey of existing conditions of TB walls continued during 2014 along the walls of Terrace Building 7. Works were carried out by the documentation team from the University of Pennsylvania under the direction of Meredith Keller assisted by Nityaa Iyer and Jocelyn Chan.

As every season, maintenance of the soft caps installed on the treated walls of TB1, TB2 and TB3 was also completed. Removal of unwanted vegetation from the caps was coordinated and carried out by Naomi Miller. A description of her work is included in the appendix section of the present report. Unfortunately, installation of new soft caps along the newly treated walls during fieldwork was interrupted this season due to the scarcity of Poa grasses in the area surrounding the mound. In fact, the winter and early spring of 2013/2014 were extraordinarily dry, with fairly heavy late rains at the end of May and beginning of June. This regime was unfavorable to annuals and perennial seed production (especially for the grasses) was remarkably low.

A summary of works completed during the 2014 season include:

Masonry consolidation of TB5-e-7, TB5-e-8, TB5-e-13 and TB5-e-14

These walls represent the elevations of the interior walls that separate the ante-room from the rest of the unit inside TB5. All walls showed traces of the original doorjambs located at the center of the room in the area where probably a door was placed to connect the ante-room with the rest of the unit During the 2013 field season, the walls were exposed, surveyed and covered again with reburial material bagged in burlap or plastic bags placed along both sides of the masonry and a temporary capping system of plastic sheeting, stone edging and a mixture of sand and clay placed on top. Unstable areas of the wall with great splay along TB5-e-8 and TB5-e-13 were first shored with wooden posts and planks and then covered with reburial material. During 2014, the bagged backfilled material covering the walls was removed and cleaning of the masonry was carried out by hand and with great attention in order to avoid collapse. Where required, shoring was temporary left in place.

TB5-e-7 and TB5-e-8 are the east and west elevations of the wall located at the insertion of TB5-e- 6. The wall is approximately 4,60 meters long with a variable height of 1,30 meters at the intersection with TB5-e-6 and 0,50 meters at the other end of the wall in the area of the doorjamb toward the middle of the room. The masonry at the intersection with TB5-e-6 is a restoration using small blocks of reddish stone set in mortar. The work was conducted between the late 1990s and beginning of 2000 by Mark Goodman during works inside TB4. The original portion of masonry is splayed toward the exterior of the wall with most of the large blocks fractured in place. The blocks in the area of the doorjamb present great deterioration and disaggregation. As with other walls, dismantling of all original blocks along both TB5-e-7 and TB5-e-8 elevations was necessary because the fractures in the blocks made impracticable the installation of stainless-steel cable reinforcement inside the core. As for the interior walls inside TB1 and TB2, during the dismantling process of this wall it came to light that it was originally constructed with large blocks, some of them placed across like big header stones. All of the large blocks were found fractured still in position or splayed from the wall, which probably occurred during the fire and collapse of the roof. These large stones were carefully dismantled piece by piece and adhered together with epoxy resins or grouted piece by piece in place.

TB5-e-13 and TB5-e-14 are the west and east elevations of the other single wall at the intersection with TB5-e-4 in the interior of TB5. The approximate length of this wall is 4,55 meters with a maximum height of 1,10 meters at the intersection with TB5-e-4 and a minimum of 0,40 meters at the doorjamb. The remaining masonry along both elevations of the wall is all original and formed by large blocks, some showing fractures. As described for the other interior wall, the masonry of this wall is splayed toward the outer side and this deformation is more evident along TB5-e-13 near the area of the doorjamb. The blocks along both elevations of the wall were more intact and only a few of them fractured. Therefore, dismantling of masonry was very limited because it was possible to keep most of the masonry in its splayed position by inserting a stainless-steel cable system in the wall core to retrofit the masonry.

Masonry consolidation works were carried out as follows:

Masonry consolidation of TB5-e-1 and TB5-e-5

TB5-e-1 and TB5-e-5 represent the exterior and interior elevations respectively of the northeastern wall of TB5. Unlike the other TB5 walls described above, these elevations were first exposed during 2014 fieldworks and stabilized immediately after completing site photography and survey of conditions.

Most of the masonry along TB5-e-1 (exterior elevation) was found exposed with the exception of the northern side by TB6 where the wall was buttressed with soil. Once cleaned, the wall is three stone courses high with a fourth course showing at the intersection with TB4 on the south side and at TB6 on the north. The total length of the wall is almost 11 meters and the width of the wall is approximately 1,40 meters. All the original masonry along the southern 1/3 of the wall was found in good condition without major structural problems. Most of the blocks of this section presented fractures so they were removed and repaired with epoxy and then used during reconstruction. On the other hand, the withstanding masonry along the middle and northern end of the wall was formed by highly deteriorated blocks showing fractures, loss, flaking and disaggregation so new stone replacement was the only possible remedy during the stabilization of the wall. Due to the unstable conditions of the northern portion of masonry by the corner with TB5-e-4, masonry stabilization of this section will be completed next season together with the walls of TB6.

TB5-e-5 is the interior elevation of the northeastern wall of TB5 that is visible from the interior of the unit. Most of the masonry along this elevation was found covered by soil. The south side by TB4 and the north by TB6 were covered by backfilling material placed by Mark Goodman in the late 1990’s while the soil covering the center of the wall was placed in the late 1950’s or early 1960’s to backfill the archaeological remains of the grinding stations found along the wall. The stabilization approach selected for this elevation was to remove the portions of backfilled material applied by Goodman and to limit exposure of the masonry by leaving the soil in the center of the wall in order to preserve the archaeological remains. Only the top stone course was exposed and treated in place. Masonry stabilization was completed along the south portion of masonry by TB4 and along the top masonry course in the middle of the wall. The northern portion of the wall by TB6 was temporary backfilled and will be treated together with TB5-e-4 next season.

Masonry consolidation works were carried out as follows:

Exposure and reburial of TB6-e-3, TB7-e-6, TBR-32, TB7-e-7, TB7-e-8, TBR-34, TB7-e-13, TB7-e-14, TBR-35, TB7-e-12, TB8-e-12, and the west section of TBR-36

Like every field season, the wall documentation team from the University of Pennsylvania returned to the Citadel during 2014. The focus of the team was the photography and documentation of the existing conditions found in the walls of TB7. Removal of the temporary reburial material to expose the masonry was carried out by the labor team along TB6-e-3, TB7-e-6, TBR-32, TB7-e-7, TB7-e- 8, TBR-34, TB7-e-13, TB7-e-14, TBR-35, TB7-e-12, TB8-e-12, and the west section of TBR-36. While exposing the walls portions of original mud-plaster covering large areas of the walls came to light in very poor and fragile conditions. Once all walls and wall tops were fully documented they were covered again with backfilling material that will stay in place until final stabilization works are carried out in the future. For recovering the walls, all material removed during clearance works was saved and bagged in plastic or burlap bags and then reused during backfilling. This system of wall protection with bags filled with debris has proved quite successful because it makes the process of reburial and exposure more efficient in terms of time and labor.

Works were carried out as follows:

Early Phrygian Gate

First excavated in the 1950’s, the Early Phrygian Gate is the most complete extant gate to survive from the Iron Age in Asia Minor. However, its dry laid construction leaves it vulnerable to the region’s high seismic activity. Constructed around 900 BCE, the gate served only briefly as the main entryway to the Citadel. Successive periods of occupation within the Citadel mound resulted in further building campaigns which incorporated the earlier structure as the foundation for new construction. The resulting changes from subsequent loading caused a series of visible conditions, most notably cracking and displacement. Although cracking occurred historically from the additional loads of the later city walls, displacement continues to be an active condition. From 2006 to 2010, the Architectural Conservation Laboratory of the University of Pennsylvania documented, monitored and assessed the gate’s overall structural stability to determine the condition of its limestone and rhyolite walls (from “Gordion Awakened. Conserving a Phrygian Landscape”, 2011).

In 2012 David Biggs from Biggs Consulting Engineering, joined the Gordion conservation team to study the walls of the Early Phrygian gate. After significant site investigations and observations of the gate walls during his first visit to Gordion, Mr. Biggs put together a number of recommendations for the structural strengthening and stabilization of the gate. The second visit to Gordion in 2013 involved additional investigations on the gate. These included excavations at the South Court walls which provided additional data to structurally analyze the court walls for seismic effects and make long-term recommendations regarding the Middle Phrygian fill around the court walls. In addition, non-destructive scanning of the North Court walls provided essential data for evaluating the structural condition of the walls and estimate the amount of voids within the masonry. Ayşem Kιlιnç, architect and conservation graduate from the University of Pennsylvania was hired to help David Biggs with preparation of preliminary works at the gate. She also played a key role in contacting local Turkish firms and contractors for the manufacturing of scaffolding and design of a gantry crane to be used in masonry dismantling.

During the field 2014 season, David Biggs and Ayşem Kιlιnç returned to Gordion to organize preliminary works at the gate that included the installation of a soil sub-base, a timber mat as scaffolding foundation and a metal scaffolding along the north and east walls of the south court. Ayşem also completed construction documents necessary for masonry intervention. In addition, masonry repointing works started along the east elevation of the south court. The following is a summary of field activities:

Soil Leveling along the center pathway of the gate:

Timber Mat Foundation:


Masonry Works:

The team contacted Schilling Germany through the local firm of Mr. Ahmet Kadioglu in Ankara for the manufacturing and purchasing of an aluminum gantry-crane to be used in the partial dismantling of stone blocks along the bulged area of the gate. A final design and price from Schilling were received in September 2014 and enough funds where left unspent after fieldworks to be used in purchasing the gantry crane.

Visitor Circuit

Since 2009, the conservation team of the University of Pennsylvania has been making incremental improvements to the visitor path of the Gordion Citadel. Since then, various prototypes of canopied pavilions and new informative signs have been proposed in addition to construction of new stone stairs and paths, and installation of new galvanized cable fencing.

During the field season of 2014, installation of new fencing along the visitor path continued along the northwest side of the Citadel between visitor information panels 4 and 6. The escarpments along this area contained several unstable soil portions protruding from the upper areas of the scarps with basal erosion and undercuts due to the effect of erosion. The approach used was to pull back the position of the fence and the visitor information panels, cut back the protruding areas of soil and use the removed soil in filling and leveling the areas of undercuts.

A condition assessment of the escarpments around the perimeter of the excavation area was completed. This information was used to develop a catalog of ways to cut or fill the escarpments in order to create a stabilization plan. For more information refer to Angelina Jones’s field report 2014.

The following is a summary of works:

Consolidation of unstable scarps

New Fence

Since 2009, the old rusted barbed-wire fencing has been gradually replaced with a new system of galvanized piping and cable to allow for maximum visibility into the Citadel Mound. The new fence follows the design proposal from Lindsay Falck. It consists of 3 mm galvanized pipes of 48 mm diameter placed at approximately 3 meter intervals, with drilled holes for five rows of galvanized cable at 25 centimeter intervals. Two pieces of galvanized cables across each panel block the entrance of large animals to the interior of the citadel. The galvanized cable is fixed to the pipes with stainless steel anchors and turnbuckles serve to tense the cables in place.

In 2014, approximately 28 galvanized pipes of the new fence were installed along the visitor path on the north section between information panels 5 and 6. The new fence was assembled and installed by a special team of local laborers under the direction of Őmür Atιtιğ, site foreman trained by Angelo Lanza. New fence installation works included:

During the 2015 spring an herbicide adapted to the vegetation of the mound will be tested to prevent weeds from growing in the joints of the masonry in the new stairs and paths. The application of the herbicide will only be limited to the top and sides of steps and paths. The efficacy of this treatment will be evaluated during next field season of 2015 in order to decide if this treatment could be part of the seasonal maintenance activities along the visitor circuit.

Pebble Mosaic Panel

Four panels from the Megaron 2 mosaic pavement in display at the Gordion museum were identified for conservation treatments during the 2011 field season. In August 2013 one of these four panels, panel 7, was lifted from display and stored at the museum during the off-season months. In June 2014 the panel was removed from storage and conservation treatments begun following a program of research and treatment testing at the University of Pennsylvania September 2013 – May 2014.

The main scope of the intervention was the removal of the heavy iron reinforced concrete from the back of the panel and replacement with a new backing system for greater stability and lighter weight. In addition, the decrease of weight will also help in the transportation of the mosaic panel to the United States for the Gordion exhibition at the Museum of the University of Pennsylvania scheduled for 2015.

A system using a Bosch router adapted for use as grinding tool to remove the concrete backing of the lifted panel was designed on site with the help of Mitchell Bring, SUNY Buffalo. A working table and scaffolding frame for the grinding operation were custom made on site by Angelo Lanza with the help of the site laborers. Grinding of the concrete backing and conservation treatments were implemented by Kevin Wohlgemuth, Meredith Keller and Jocelyn Chan under the supervision of Frank Matero. In addition, Sema Kurekci1, Jessica Johnson, William Shelley and Cricket Harbeck helped the team with testing of different treatments on the pebbles of the mosaics in display and finishing the concrete backing of the lifted panel.

The following steps summarize the conservation intervention of the lifted mosaic panel during the field season of 2014:

Other treatment options were also explored on several mosaic panels on display at the museum. One test treatment was the removal of the cementitious overgrout, a prevalent condition affecting many of the panels that conceals the faces of the panels and distorts the display’s design and integrity. Additionally, various pebble compensation methods were explored in areas of both historic and recent loss. For detailed information of these treatments refer to the 2014 mosaic field reports.


1Senior Conservator from the Museum of Anatolian Civilizations (Ankara)

2The concrete side of the panel was exposed for the first time to the team after flipping the mosaic.

3CNC stands for Computer Numerical Control.

4For details on the treatment of the concrete backing and protection of the metal reinforcement please refer to Kevin Wohlgemuth’s field report 2014.

5Archaeologist and Ankara Representative of the Ministry of Culture and Tourism


Project Director: Frank G. Matero

Project Supervising Conservator: Elisa Del Bono

Project Team: Angelo Lanza, Meredith Keller, Ayşem Kιlιnç, David Biggs, Mitchell Bring, Sema Kurekci, Giuseppe Bomba, Angelina Jones, Kevin Wohlgemuth, Nityaa Iyer, Jocelyn Chan