The Lakatnik (Milanovo) Rocks are a protected area, part of Vratsa Balkan Nature Park, with diverse climbing routes. The rocks are located on the left bank of the Iskar River and fall within the territory of Milanovo village (old Osikovo), which is why they are also called Osikovo Stones.

In these rock massifs, over 100 caves and chasms have been formed, the longest of which is "Temnata Dupka" with a length of over 5 km. The area is extremely attractive for mountaineers and cavers, and due to its beauty — also for tourists.

It is one of the most visited and famous climbing sites in Bulgaria and is considered the founder of Bulgarian rock climbing. The "Temnata Dupka" cave is the "school" of Sofia cavers.