Borek, Flooded serpentinite quarry near Borek, Czech Republic

Borek quarry is a flooded serpentinite quarry of about 2 hectares near the village of Borek, between Chotěboř and Golčův Jeníkov. On its western edge, at 424 metres above sea level, lies the Borecká skalka nature monument, a remnant of dry pasture on exposed serpentinite bedrock.

Serpentinite, a magnesium-rich rock, was mined here from the end of the Second World War until 1992. After extraction stopped, the roughly 2-hectare pit filled with water and became a diving site.

The quarry is now a diving site where an articulated Ikarus bus was sunk in 2003 and still stands on the bottom with its windows and engine intact. Divers also pass a stripped Wartburg car wreck and the "Stejskanik", a former tank converted into a submarine. Perch, carp, pike, catfish, zander and crayfish live in the water.

The site is now accessible as a flooded lake, but visitors should be aware of its depth and water conditions. Learning about safety considerations and current conditions is wise before approaching.

The flooded site reaches depths of around 30 meters and attracts divers who document underwater discoveries. One notable find is a submerged articulated bus resting on the bottom.