What is the largest island in a lake on an island?
The largest island in a lake on an island is Pulau Samosir in Danau Toba on Sumatra. Samosir in Lake Toba, Indonesia – 630 km2 (240 sq mi), was originally formed as a peninsula; its current island status, however, is only through its deliberate separation from the mainland by a canal.
Answers by country
the United States