The lonely island

You're looking at the only island on the whole surface of a lake that sits on the border of two US states and covers almost 520 square kilometres. Protected within California's Emerald Bay State Park, Fannette Island is the only bit of land that manages to breach the waters of Lake Tahoe. Most of the lake's topography is submerged in a basin that reaches down more than 500 metres. The exceptional depth means that Tahoe Tessie, a legendary lake monster supposedly seen in these parts, has 150 cubic kilometres of water to explore here in the USA's most voluminous lake barring the Great Lakes.