Lukina jama is the deepest cave in Croatia and one of the deepest in the world, plunging down an incredible 1431 meters. It's a place that impresses purely through scale - a vertical abyss hidden high in the Velebit mountains, accessible only to experienced cavers, yet a captivating story for anyone fascinated by the underground world.

The cave lies within the strict nature reserve of Hajdučki and Rožanski kukovi, inside Sjeverni Velebit National Park - one of the wildest and most remote corners of Croatia's mountains. The surrounding landscape is rugged limestone wilderness, where wind whistles between rocky formations and patches of snow and ice can be found tucked deep into crevices even in summer - inside the cave itself, ice and snow cling to the walls down to a depth of 320 meters. It's a stark, silent and majestic landscape, especially striking at dawn and dusk when Velebit's ridges glow in shades of grey and beige.

How to get there

• The cave entrance lies in a remote part of Sjeverni Velebit National Park - reaching it requires a long, demanding hike along the park's mountain trails, recommended only for experienced hikers
• The cave itself is accessible only to qualified cavers with proper equipment and permits - it is not a tourist trail

Practical information

• The entrance is a crack-shaped opening measuring 22.5 × 5 m
• Exploring the cave requires professional caving skills and permission from the national park authorities
• The area is under strict nature protection as part of the Hajdučki and Rožanski kukovi reserve

The cave was discovered by Slovak cavers in 1991, and it's named after Ozren Lukić, known as Luka, a caver who died as a Croatian soldier during the homeland war on Velebit. At the very bottom, just 54 meters above sea level, researchers also discovered an endemic leech species previously unknown to science.