Heligholmen

Very nice underwater landscape, cauldrons and passages to swim around in. Lots of fossils to look at.

According to legend, there is a whole treasure of gold coins scattered on the bottom of the island.

Things to consider: The current! Wading out to the island can be downright dangerous if there is a current. A German family got swept away a couple of years ago when they were on their way out and were then swept away by the current.

How to get there: Go down to Sudret (the southernmost cape on Gotland). Then head towards Holmhällar. There you will see the island, then find the path where you can wade out to the island. Wade, swim or take a boat out to the island (but be aware of the current).