More than 300 wheel crosses poke above the ground in this small cemetery on an Estonian island, some just barely visible above the tufts of grass. The distinct ringed crosses look out of place amid the newer, more traditional designs found atop nearby plots.

The crosses date to anywhere from 1743 to 1923. Because of the circle, they’re frequently referred to as Celtic crosses. But the arms of the cross hardly extend beyond the circle, making the markers look more like the wheel crosses found in pre-Christian religious symbolism.

The unusual grave markers are leftover relics from when Estonian Swedes lived on the island. The islanders carved names, dates, family symbols, and other notes into the limestone and sandstone headstones. This particular style of cross is unique in Estonia, and is only found within places settled by the Coastal Swedes.

Vormsi was inhabited by Estonian Swedes for much of its history, from the 13th century up until World War II. Almost all of the island’s residents were either evacuate to or fled to Sweden during the war. Now, only about 400 people live on Vormsi.