Charles Island is a 14-acre island located roughly 0.5 mile off the coast of Milford, Connecticut, in Long Island Sound centered at 41°11′28.32″N 73°03′18″W / 41.1912000°N 73.05500°W. Charles Island is accessible from shore via a tombolo, which is exposed at low tide. According to early local histories, the Sachem Ansantawae resided there during the su…Charles Island is a 14-acre island located roughly 0.5 mile off the coast of Milford, Connecticut, in Long Island Sound centered at 41°11′28.32″N 73°03′18″W / 41.1912000°N 73.05500°W. Charles Island is accessible from shore via a tombolo, which is exposed at low tide. According to early local histories, the Sachem Ansantawae resided there during the summer months. European discovery of the island occurred in 1614 when Adriaen Block sailed through and mapped Long Island Sound. The island appears on his hand-drawn map found in The Netherlands National Archives.