The Bozkov Dolomite Caves hide the largest underground lake in the Czech Republic and are the only cave system in the country formed entirely in calcareous dolomite. With their extraordinary eccentric stalactites, crystal-clear blue-green waters and dramatic lighting effects, these caves offer an underground experience that genuinely surprises even seasoned cave visitors.

Situated in the Železný Brod Highlands at an elevation of 425–485 m, just one kilometre north of the village of Bozkov, the caves maintain a constant temperature of 7.6°C year-round — refreshingly cool in summer and a welcome shelter in winter. The 400-metre tourist trail conquers around 300 steps and takes you through two connected systems: the Old and New Caves, linked by an impressive 50-metre artificial tunnel. Along the way you pass through evocatively named chambers — the eerily red-lit Hell, the Pirate's Corridor, the Robber's Cave — before arriving at the grand finale: the Lake Dome, where a 320 m² underground lake glimmers in the torchlight. The cave decoration is truly unique: alongside classic stalactites and stalagmites you'll find delicate fibrous and shrub-like excentric formations, quartz ledges and lace-like structures dissolved by acidic water.

Above ground, the surrounding mixed forest is home to spring snowflakes in early spring, while inside the caves four bat species roost, including the lesser horseshoe bat.

• Bozkov village — large car park on the northern edge of the village, short walk to the cave entrance — easy
• Jesenný railway station — access path leading to the caves — easy, moderate walking time
• Bus line Semily–Vysoké nad Jizerou, stop at the church in Bozkov

• Tourist trail length: 400 m, approximately 300 steps
• Inside temperature: constant 7.6°C — bring a warm layer
• Open year-round; closed every Monday
• Operated by the Cave Administration of the Czech Republic
• National Natural Monument status since 1999

The caves were discovered only in 1947 during quarry blasting, yet they had been hiding just a few metres underground for millions of years — a reminder that the earth still holds plenty of secrets.