Historical cities have multi-layered characters composed of the physical traces of previous civilizations. The preservation and presentation of archaeological values in historical cities require good planning. Whether the archaeological values are indoors or outdoors, it is necessary to protect them and make them visible to demonstrate the historical process. The preservation of archaeological values encountered during the restoration works of historical buildings affects both layers. The decision on how visible an archaeological value should be, for documenting and demonstrating the historical process, needs to be clarified within the restoration efforts. The harmony, accessibility, and visibility of both periods should be ensured in the interventions for the protection and presentation of the existing historical buildings and archaeological values.

In this study, the İbrahim Pasha Palace (Turk and Islamic Art Museum) and the Beyazıt Imaret (Beyazıt Manuscript Library) buildings are used. The restoration work at Ibrahim Pasha Palace began in October 2012 under the title “Turk and Islamic Art Museum Restoration Merchandising and Landscaping Project.” Concrete cleaning works started in the courtyard of the existing historical building on March 28, 2013. During this cleaning work, remains of graves and a hippodrome from the Byzantine period were encountered at the basement level of the museum. Approximately two years later, on December 25, 2014, the landscaping project, which included architectural interventions for the archaeological value, was approved.

At Istanbul Beyazıt Imaret, excavation work began in the inner garden under museum supervision based on the decision of the preservation committee. This excavation work was not part of the restoration project but was included as a functional need for the proposed technical rooms. During survey drilling in an area of approximately 55 square meters, an archaeological value in the shape of a semi-circle with a diameter of 2.3 meters, a width of 60 cm, and a depth of 25 cm made from cut stone-Khorasan mortar was found at a depth of 2.2 meters from the ground. For the archaeological values discovered during the excavation, the related preservation committee approved the restoration project on May 22, 2013, and the project was completed in 1 year. The discovery and preservation efforts for the archaeological values combined took about 2 years. On December 16, 2016, problems related to the archaeological value were determined by the regional conservation council.

In both examples of archaeological values, some problems were identified in the preservation of archaeological values and their compatibility with the existing historical buildings. After the decision of The High Council for the Historical Real Estate and Monuments in 1966 to use Ibrahim Pasha Palace as the Turk and Islamic Art Museum, it was suggested that the heating system could be placed underground in the inner garden in 1975. The heating system remained buried where the archaeological value was discovered, above the remains of the hippodrome, until 2012. Even in a historical building used as a museum and being public property, architectural presentation efforts began in 2013 for an archaeological value that was discovered in 1975. At Beyazıt Manuscript Library, which does not have a museum function, a correlation between Byzantine art and the registered historical building was not achieved, and access and awareness of visitors to the area where the archaeological value is located were very limited.

In both examples, the archaeological values were covered from the top with glass structures. However, at the Turk and Islamic Art Museum, the guardrails surrounding the glass enclosure for safety purposes prevent visitors from observing the archaeological values. Additionally, the designed glass enclosures do not allow the values to be sufficiently perceived. Furthermore, the glass slab structure built to enable observation at Beyazıt Imaret experienced structural deformations after a short time. The physical conditions of the structure were not adequately considered when making additions for urban archaeological values, leading to heavy moisture and moss development on the remains and walls of the new construction. 

Archaeological values presented with the help of modern technology should have observation systems in place, and changes should be constantly tracked. However, archaeological values that have undergone preservation and architectural presentation efforts often lack plans for administrative inspections at certain intervals following completion. At Beyazıt Imaret, preservation and architectural presentation work was carried out on archaeological values discovered in 2012 during excavations for the construction of technical spaces. Problems were discovered during inspections conducted three years after the completion of the preservation work. In both cases studied in this research, no informative boards were found outside the structure related to the Byzantine period archaeological values found within. This impacts the awareness of these values and creates the risk of them being “forgotten.” 

In conclusion, achieving the co-occurrence of archaeological values from the Byzantine period with the historical buildings they are situated in is an important tool for displaying the historical continuity of cities. Therefore, in multi-layered structures, the togetherness, accessibility, and visibility of different periods should be evaluated together during preservation planning. This planning process should be inclusive of all parties involved, and participation from all parties should be encouraged. In addition, related institutions should be included in the development process. Emergency preservation methods to stabilize the current condition of archaeological values, which were buried underground and have material deformations and structural problems, should be developed. The design process should focus on preserving archaeological values with minimal interference.