Soisalo, a 1,638 km2 (632 sq mi) body of land in Finland that is surrounded by individual lakes (Kallavesi, Suvasvesi, Kermajärvi, Ruokovesi, Haukivesi and Unnukka) connected by creeks and rivers – rather than sitting within an individual lake – was suggested in a 1987 study as an island, due to being effectively "surrounded by water".[4] Other scientists rebut this claim,[4] noting that the waters surrounding Soisalo are not on the same level, with elevation differences up to 6 m (20 ft) between the surrounding lakes, and does not meet the criteria of a true island.[4] Samosir, a 630 km2 (240 sq mi) body of land in Lake Toba, Indonesia, is a peninsula that is technically surrounded by water only because a canal was built across it, effectively separating it from the mainland.