The entrance of the Bulak (Mencilis) Cave, which is located within the borders of Karabük Central Bulak Village and also border with Safranbolu District, is on steep rocks and the length of the cave is 6.5 kilometers. 2.5 kilometers of the cave has been mapped, and the 380-meter section has been opened to tourism by electrification and a walking track. It is still a hydrologically active cave. Underground rivers, ponds, waterfalls, interesting and extraordinary stalactite and stalagmite formations and registered as "Natural Assets" attract the attention of researchers and visitors.