Lilla Karlsö

Small Swedish island in the Baltic Sea

Lilla Karlsö is a small Swedish island in the Baltic Sea, situated about 3 km (1.9 mi) off the west coast of Gotland and 4.5 km (2.8 mi) from Stora Karlsö; it is part of Eksta socken. It has an area of about 1.6 km² (0.62 sq mi) and is 66 m (217 ft) high. Most of the island consists of a limestone plateau. Parts of the shoreline is bordered by steep cliffs. The island is mostly covered by alvar. There is also some very old broadleaf forest, which is unique for Gotland. There are several caves and up to 16 m (52 ft) high limestone pillars.

The island is mostly known for its rich birdlife and flora. There are colonies of several thousands pairs of guillemot and razorbill. There are also several very rare plants for Sweden such as Lactuca quercina (called 'Karlsösallat' in Swedish), hart's-tongue fern and Petrorhagia prolifera.

Since 1954, the island has been owned by the Swedish Society for Nature Conservation and it is now a nature reserve. During summer there are tour boats from Djupvik 15 km (9.3 mi) south of Klintehamn.