Kurisoo Hole

About ten thousand years ago, retreating glaciers left behind an enormous rock. It was too big to resist weathering and over some time it broke into eight large and a number of smaller rocks. These rocks are gathered close to each other on a half-hectare piece of land. When examined more closely, it can be seen which pieces fit each other.

By now, the island has accepted the rocks, found a nice place for each, suntoumded them with junipers, pines and firs and covered them with moss.

This remarkable collection of rocks was examined twice, in 1871 and 1879, by Gregor Helmersen – a Baltic German of Estonian origin, a professor at St. Petersburg Mining Institute and a member of St. Petersburg Academy of Sciences, the first chairman of Russian Geology Committee. He considered the boulders so amazing that he called it the best sample of boulders in the world. Now, his memory is saved in the name of the boulders he examined.

Kurisoo Hole is also called Kurisoo, Koolme or Neelme sinkhole. This cleft is easily mixed up with another Kurişu sinkhole in Kõrgessaare rural municipality as both are near Kurisu villages which got their names from the sinkholes. Both are good examples of karstic phenomenon,

Karstic holes can be found in several places in Hiiumaa, A karst is formed in places where the bedrock is easily soluble in water. Superficial waters are absorbed into the ground through the cavities left by dissolved rock, During spring flooding, a lake is formed in Kurisoo Hole. When the water reaches a certain level, its absorption becomes especially intensive and the lake disappears into the ground in 10-12 hours.

This phenomenon left great impression on people of the old times. Legenda describe karstic holes as mouths of evil which together with water may swallow things and animals and even people. The name “kuri suu” (evil mouth) was shortened into “kurisu.” and is up to now used as the name of large sinkholes.

Kurisoo Hole is the largest sinkhole in Hiiumaa; it is 100 meters long and 30 meters wide and it reaches down to 6 7 meters.