Everything about Sweden’s longest cave
Caving might be one of the most exciting and unique activities you can do outdoors – climbing and crawling through a labyrinth of tunnels in absolute darkness and silence, knowing that water has formed this cave for thousands and thousands of years!
Interesting facts about the Korallgrottan
The limestone cave Korallgrottan (Eng. Coral Cave) has been formed by carbonic acidic water dissolving the porous limestone, leaving cavities which grow over time. Today over 6km of the cave system have been explored and mapped, making it the longest cave in Sweden.
In the Korallgrottan you can find stalactites and stalagmites. They form when acidic water dissolves calcium carbonate in the limestone. On entering the cave, the water deposits some of the calcium carbonate which eventually forms a drip-stone. The formations of the Korallgrottan grow one centimetre in approximately a thousand years, which is very slow, even for the growth of stalactites.
The corals in the Korallgrottan are of course not actual corals like the ones you can find in coral reefs, but stone formations which look similar to corals.
Caving in the Korallgrottan
Since its discovery in 1985, the Korallgrottan was quickly made available to public. Nothing has been added to the cave – no wooden paths, lamps, stairs or hand-rails. The only non-naturalistic things you’ll find in the cave are ropes laying on the ground to mark the main tunnel to the exit and locked iron gates at the entrances. They’ve been installed for safety reasons, it’s only possible to enter the cave with guides.
Caving in the Korallgrottan is possible in summer and winter, as long as the entrance is being kept free from the ice, which would naturally seal the cave during winter. Once in the cave the temperatures are around 4 degrees Celsius, even in the summer! So, make sure to bring a long sweater and pants when visiting the cave.