SONDAGE EXPLORATIONS IN THE VELKOVA DUPKA CAVE (Stefanka Ivanova – ivanova.stefanka@gmail.com) The Velkova Dupka Cave is located in the paleo-valley of Svinski Dol, a feeder of Izvorska River. The entrance of the cave is 56 m above the bottom of Svinski Dol and 126 m above Izvorska River. Six litho-stratigraphic layers were distinguished in the profiles of the sondages that were carried out in the cave. Layers 1 and 2 were badly damaged and contained material disturbed from the clandestine digs. The material includes a number of bones and sherds of the Iron Age (1st millennium BC). Two stages of activities could be distinguished in that period. Most likely, the Thracians used the cave as a cult place. Layers 3 and 4 contain remains of the Quaternary fauna, predominantly Ursus sp., Cарrа ibex, Lepus sp., Carnivora indet. Layer 4 contains less material. Layers 5 and 6 are sterile and show a period of a powerful flood in the cave and the deposition of deep sedimentary deposits.