The excavations of 1933–42 (Jaroslaw Pasternak), 1951–52 (Karger M.K., Aulikh V.), and 1955 uncovered remains of houses, workshops, fortifications, and ten churches built of white stone. Pasternak's excavations established that ancient Halych originated on the spot of today's village Krylos (located 5 km south of modern Halych) as early as the 10th century. In 1936 Pasternak also discovered remains of an 11th to 12th century three-apse cathedral with burial tomb of Prince Yaroslav Osmomysl in it. The cathedral is ascribed to the Cathedral of the Dormition previously known only from Chronicles, known to have been a sepulchre of the earliest Halychian princes. The sheer size (37,5 by 32,4 m) of the cathedral (the second largest mediaeval church on the territory of present-day Ukraine, smaller only to St. Sophia Cathedral in Kyiv), suggests that ancient Halych was the seat of a diocese. Most likely the cathedral was built in 1157 and destroyed in 1241 by hordes of Batu Khan, then rebuilt again and last time mentioned in 1576.