Which Polish peninsula is a narrow sandbar into the Baltic Sea?

The Hel Peninsula is a narrow sandbar extending into the Baltic Sea in northern Poland. It separates the Bay of Puck from the open Baltic and is often called the Hel Spit.

The peninsula is about 35 kilometres long, but its width changes dramatically. It narrows to roughly 100 metres in places, measures around 300 metres near Jurata, and broadens to more than 3 kilometres near its tip. Because it is built entirely from sand, winter storms have sometimes cut through it and temporarily turned it into an island.

The name may derive from the Old Polish word hyl or hel, meaning an empty or exposed place, though a Germanic origin has also been proposed. The settlements of Hel, Jastarnia, Jurata, Kuźnica, and Chałupy line the peninsula, which is served by both a road and a railway.

Hel also has an important military history. Poland fortified it during the interwar period, and Polish forces defended the peninsula during the 1939 Battle of Hel. Some surviving batteries and fortifications are now tourist attractions, although parts remain military property.