Ruhnu borehole 
Ruhnu borehole
Ruhnu borehole, a borehole created in the 1970s for the purpose of national geological mapping. A metal tower was erected on the island, a drilling unit (ZIF-1200) and a power plant (Škoda) were installed, and the borehole was finished in half a year; it was the deepest one in Estonia at the time (787.4 m). The drilling process yielded the most complete cross-section of Paleozoic sedimentary rocks in Estonia (776.4 m) and the deepest crystal basement was reached (784.2 m below ground). The materials gathered from Ruhnu borehole have enabled the geological make-up of the island to be described in great detail.
The hopes of finding natural gas and oil were not fulfilled; however, mineral water was found.
Today, the location of the borehole is marked and guarded, pressurized mineral water has been cut off.
See also
Created in 2014
