This site contains two small rocky islands, called Gäddtarmen in Swedish and Hauensuoli in Finnish, near the Hanko port in the southern tip of Finland. You can get to Gäddtarmen with your own boat or with water bus in the summer. Water busses are operated by several travel companies.
Site contains many petroglyphs. Oldest are from 15th century and the newest is from 1970s. Carved petroglyphs are representing coat of arms, short messages and signatures.
Some travel companies offer guide to tell you about petroglyphs, some let you explore islands by yourself. Gäddtarmen should be only visited in summer because in winter the petroglyphs are under the snow and there are no water bus service to the islands.