Doctoral Student at HSE University Reveals Hidden Layout of Ancient Parion

Ancient Parion

© iStock

İdil Malgil, a researcher at HSE University, conducted a UAV-based LiDAR survey of the ancient Roman city of Parion in present-day Turkey. The high density of the scans allowed the team to detect subtle terrain features concealed beneath the ground and vegetation. The survey revealed traces of entire neighbourhoods, terraced structures, and walls that had remained invisible during routine excavations and could not be identified through aerial photography. The findings have been published in Ancient Civilizations from Scythia to Siberia.

Parion was likely founded at the turn of the 8th and 7th centuries BC in northwestern Turkey, in what is now Çanakkale Province, and in the 1st century BC, it became a Roman colony. Systematic archaeological excavations have been underway at Parion since 2005. Researchers have already uncovered Roman baths, a theatre, and several necropolises. However, large parts of the ancient city remain unexplored, as they are either overgrown with grass and shrubs or buried beneath a thick layer of soil.

Conventional aerial photography captures only features visible on the surface. Ground-penetrating radar can reveal what lies beneath the ground, but it produces relatively low-resolution images and is effective only over limited areas. Although archaeologists had data from previous topographic surveys, they still lacked a comprehensive understanding of the city's layout and the structures that remain buried underground.

To address this challenge, İdil Malgil, a doctoral student at the Institute for Oriental and Classical Studies of the HSE Faculty of Humanities, employed LiDAR (laser scanning) technology. 

Surveys of this kind have previously been conducted in archaeological excavations, for example in South America, where LiDAR’s ability to penetrate dense tropical forest canopy is particularly valuable. However, the Parion study is one of the largest UAV-based surveys ever carried out in northwestern Anatolia.

İdil Malgil

'Unlike a conventional camera, a laser beam can pass through gaps between leaves and tree branches. The reflected signals are then processed by a computer, which filters out reflections from vegetation and retains only the laser pulses that reach the ground and return to the drone’s receiver. The result is a digital model of the terrain, as if all vegetation and structures had been removed,' the researcher explains. 

Additional visualisation algorithms functioned like a digital filter, detecting and highlighting even the smallest terrain irregularities. For example, the Sky-View Factor illustrates how open a location is to the sky: enclosed depressions appear dark, while elevated areas appear light, helping identify features such as artificial terraces or moats. In archaeology, this method is used to detect micro-topographic anomalies, including buried ruins, walls, ditches, and mounds. It is based on high-resolution digital terrain models. Unlike traditional topographic visualisations, which simulate a single light source, the Sky-View Factor calculates the proportion of the sky hemisphere visible from any given point on the Earth's surface.

Orthophotographic map of Parion (Ancient Civilizations from Scythia to Siberia)

© İdil Malgil

The UAV completed seven flights over Parion, with a total data acquisition time of 90 minutes. The resulting point density of 796 points per square metre is considered exceptionally high, even for the most demanding archaeological applications. For comparison, conventional airborne laser scanning from aircraft typically yields between one and eight points per square metre, with high-end systems reaching up to 60 points. UAV-based scanning made it possible to visualise objects measuring just a few centimetres in size. 

'The density of 796 points/m² represents a fundamentally new level of detail. We can now visualise not only large underground structures but also individual walls, structural corners, and a system of terraces that were previously indistinguishable against the natural terrain background,' comments İdil Malgil.

The most significant findings were made on the acropolis of Parion, located on the rocky cape of Bodrum. Because the area was not subject to intensive agriculture, the underground structures have remained well preserved. 

The researchers were able to identify a rectangular building to the north of the previously known excavation area, as well as a group of walls and terraces in the northwestern part of the cape. The orientation of these features varies between 74 and 120 degrees, which, according to the author, suggests a deliberate adaptation of the urban layout to the complex natural terrain.

The data obtained does not replace traditional excavations; however, instead of digging indiscriminately across the site, archaeologists can now target specific areas where structures are most likely to be located.