Lake Plateliai (Samogitian dialect: Plateliu ežers) is the biggest lake in Samogitia and 9th biggest in Lithuania. It is the central attraction in the Žemaitija National Park. It covers about 12 km² and reaches up to 49 m in depth. It has seven islands, one of them housed a castle and now is called Castle Island. Archeologists found remains of two castles and think it might be the Queen Bona castle. The lake has both diving and yacht clubs. Plateliai town is located on the west bank of the lake.