Larsen Harbour is a narrow 2.6 miles (4.2 km) long inlet of indenting volcanic rocks and sheeted dykes known as the Larsen Harbour Formation. It is a branch of Drygalski Fjord, entered 2.5 miles (4 km) west-northwest of Nattriss Head, at the southeast end of South Georgia. It was charted by the German Antarctic Expedition, 1911–12, under Filchner, who named it for Captain Carl Anton Larsen a Norwegian Antarctic Explorer, who made significant contributions to the exploration of Antarctica. The most significant being the first discovery of fossils, for which he received the Back Grant from the Royal Geographical Society.