Ground-Penetrating Radar Investigation of an Underwater Settlement Site at Koorküla Valgjärv

The purpose of the ground-penetrating radar survey conducted in 2024 at the site of the remains of underwater structures in Koorküla Valgjärv was to map the extent of the prehistoric structure and assess the thickness of the cultural layer. The results show that the lake bottom is mostly 2–3 metres deep in the survey area, but less than a metre of water covers the top of the mound. A strong horizontal reflection was detected at the top of the mound, which may indicate a horizontal surface of a cultural layer (up to 90 cm thick) mixed with lake sediments. The georadar survey confirms that the potential archaeological area is more extensive (over 16,000 m²) and partially concealed by lake sediments, which increases the need for additional underwater archaeological excavations.