Hulubergsgrottan. Sipoo, Finland. Tiny hole, only crawable. And now filled with dirty water. What could be more fun to explore?
Hulubergsgrottan is one of the few karst caves in Finland. It has been formed as part of a chemical process where water dissolves certain types of rock. This cave is just a few meters long, but still offers a nice caving experience given its low ceiling and hidden opening in the thick forest around it.
The cave has two chambers, the first of which is sometimes free of water. But not on our visit; we had to crawl in the water and mud to move around. The cave's ceiling is nice and for-Finland-rare limestone. At the end of the main chamber there is a hole that should continue to the second chamber, but we were unable to enter there with all the water filling the tunnel.
The article in retkipaikka by Antti Huttunen is the best resource for this cave. Antti has also visited the second chamber in the cave. The coordinates of the cave are N 60° 19.406' E 25° 16.633'. The cave is protected; treat it with care.