The article presents the experience of the Institute of Archeology of the Russian Academy of Science’s Markul Expedition, which utilized digital technologies for the study, preservation, and popularization of cultural heritage. The objective of the Markul Expedition was to obtain a complete picture of the historical and cultural landscape of Northwestern Colchis in antiquity by applying two key digital technologies: geographic information systems (GIS) and photogrammetry. The results obtained from the latter were used both independently and were integrated into GIS as separate layers (orthophotomaps, digital terrain models) or as hyperlinks to objects (3D models, videos, plans, sections, etc.). The objects investigated by the expedition are very diverse both in size and in terms of shooting conditions. Accordingly, each category of archaeological site required an individual approach, and a separate methodology and equipment. The final visualization angles differ to a fair extent from the original samples even though photogrammetry provides more accurate results than manual measurements. There are several reasons for this, including the vegetation, which is a dominant factor in the Caucasus subtropical area and led to partial visual distortions of the photographed objects. For this reason, the final projections of architectural forms required corrections and some hand drawing. In this process, new aspects appeared in the final result, resulting from the archaeologist and artist’s differing views of the objects. Our experience of using modern remote sensing technologies is also presented in the article.

The present study examined the references in the works of ancient authors to the ancient city and the Roman fortress Pitiunt, the geological aspects of the formation of the coastline in the Pitsunda Cape area in the first centuries AD and the results of archaeological research of the monument performed from 1952 to 1974. The creation of the 3D reconstruction of the exterior of the Pitiunt fortress during its prosperity in the IV century AD, along with the churches which were the first monuments of religious architecture in northwestern Colchis (northwestern Colchis comprises parts of the territory of modern Russia, Georgia and Abkhazia) was carried out based on the excavation plans and the principles of fortification and temple architecture that were accepted in the late Roman times, paying special attention to the geological paleoreconstructions.

In Late Antiquity and the Early Middle Ages, both coastal and sub-mountainous parts of Colchis underwent rapid urbanization. In the 12th century, the processes of decline began: Large settlements were replaced by small farmsteads with light wooden buildings, and the economy transformed from commodity-based to subsistence-based. What caused this decline? Was it the social and political events linked to the decline of the Byzantine Empire and changes to world trade routes, or were there other reasons? This article provides the answer. The synergy of archaeological, folkloristic, historical cartographic, climatological, seismological, and hydrological data depicts a strong link between these processes and climate change, which occurred at the turn of the 12th–13th centuries. The beginning of cooling led to a crisis in agriculture. A decline in both farming and cattle breeding could not fail to affect demography. Seismic activity, noted in the same period, led to the destruction of many buildings, including temples, and fortresses, and changes in hydrological networks, which were directly linked to climate change and caused water logging, led to a loss of the functions of coastal areas and their disappearance.

The 3D reconstruction of the Great Pitiunt Fortress has been our long-term goal. The results of archaeological excavations have revealed traces of a mosaic floor in one of the temples. It was impossible to carry out a full reconstruction of the temple without first restoring the mosaic floor. The area of the preserved mosaic found during the excavations was only 33 square meters. This is 10.5% of the total interior area of the temple of 317 square meters. However, based on a number of reasons, i.e., the direction of the dividing borders between the elements of the mosaic, the requirement of symmetry of individual sections, the adjustment of motifs and the analysis of similar contemporaneous sites, it was possible to make a version of the general view of the reconstructed mosaic floor for further processing in the 3D reconstruction of the temples of the complex. This article provides the methods described, an analysis and justification of the reconstructed design of the mosaic in fragments and a holistic final model. The stylistic features of the mosaic have been identified, and the reasons for the dating of the mosaic have been given.