Lake Biwa Museum — Freshwater Lake Ecosystem & Cultural History

Lake Biwa Museum (琵琶湖博物館) is a comprehensive natural history and cultural museum dedicated to Lake Biwa's 4-million-year history, ecosystem, and relationship with humans. The museum features aquarium galleries with Lake Biwa native species (including the giant Biwa catfish and ancient endemic species), dioramas of prehistoric Lake Biwa, and exhibits on the lake's geological formation, water quality, and cultural significance to Kansai region.

The museum's unique focus — freshwater lake ecology rather than marine — makes it distinct from typical Japanese aquariums. The 'Ancient Lake' exhibits explain how Lake Biwa's extreme age (one of the world's 20 oldest lakes) allowed unique endemic species to evolve found nowhere else. The museum also addresses modern environmental challenges — pollution, invasive species, and watershed management.