The Curonian (Courish) Spit is a 98-kilometre (61 miles) long, thin, curved sand-dune spit that separates the Curonian Lagoon from the Baltic Sea. Its southern portion is in Kaliningrad Oblast, Russia. The northern part is in Klaipėda County, Lithuania. It is a UNESCO World Heritage Site shared by Lithuania and Russia.^[1]

The Teutonic Knights occupied the area in the 13th century. They built castles at Memel (1252), Neuhausen (1283), and Rossitten (1372).

From the 18th century, it was part of the Kingdom of Prussia. The Prussian government sponsored large-scale revegetation and reforestation after the trees were cut down to make ships.

The Curonian Spit has the highest moving (drifting) sand dunes in Europe. The average height is 35 metres (115 ft), but some get to 60 metres (200 ft).