Ochtinská Aragonite Cave is one of only three aragonite caves open to visitors anywhere in the world — and arguably the most spectacular of them all. Hidden beneath the Hrádok hill in the Revúca Highlands of Slovakia, it dazzles with twisted helictites, needle-like aragonite crystals and bizarre 'iron flowers' that grow in every direction, defying gravity. It is a UNESCO World Heritage Site and a place that genuinely has to be seen to be believed.

The cave maintains a constant temperature of just 7.2 to 7.8°C with humidity as high as 97%, so even on a hot summer day you will want a warm layer. The artificial entrance tunnel is 144 metres long and descends 19 metres via 104 steps. The guided tour covers 230 metres and lasts about 30 minutes — short, but absolutely unforgettable. The cave sits on the northwestern slope of Hrádok hill, between the towns of Jelšava and Štítnik in the Slovak Ore Mountains.

• From Rožňava via Štítnik towards Jelšava — approx. 25 km by car
• From Jelšava towards Štítnik and Rožňava — approx. 10 km by car
• From Poprad via Vernár, Dobšiná and Štítnik — approx. 80 km by car
• Nearest bus stop: Gočaltovo, Hrádok — 300 m walk to the car park, then a short easy walk to the entrance

• Car park is located 300 m from the cave entrance
• Guided tour duration: 30 minutes
• Temperature inside: 7.2–7.8°C — bring a warm jacket
• Photography is not permitted without purchasing a special permit
• National Nature Monument and UNESCO World Heritage Site

The cave was discovered entirely by accident in 1954, when workers drilling a geological exploration tunnel broke through into its chambers — and found formations up to 138,000 years old. The second-generation aragonite is still growing today, which is why it stays a brilliant white.