Deep straits and bays around the main island
The main island is called Möja and is clearly set apart from the other Möja islands by cracks that have broken up the primary rock formations, where parts of the bedrock have sunk to form deep straits and bays. The bay west of Möja reaches a maximum depth of 134 metres.
The Björndalen nature reserve on northern Möja alternates between rocky pine forest and productive woodland, interspersed with marshland. The forest is of great scientific value, and is part of the Archipelago Foundation conservation project, “Living Archipelago”. A considerable part of the reserve is left alone to develop into natural forest. The reserve is home to an abundance of wildlife, including moose, roe deer, hares, martens, badgers and foxes. The reserve’s birdlife is of particular value.