island in Danau (lake) Toba, Sumatera Utara propinsi (North Sumatra province), Sumatra, Indone.... sq isthmus,

Approximately 200 sq mi (520 sq km) in area, the island occupies nearly half the lake and is joined to its western shore by an isthmus, at which point is the island's principal town, Pangururan. sq isthmus,