EU-053 Finland Market reef

Märket is a small 3.3-hectare (8.2-acre) uninhabited skerry in the Baltic Sea between Sweden and Finland (in the area of the autonomous Åland Islands), with a lighthouse as its salient manmade feature. Märket has been divided between the two countries since the Treaty of Fredrikshamn of 1809 defined the border between Sweden and the Russian Empire as going through the middle of the island.