Almarestäket

Almarestäket, or Stäket, is a strait at the inlet of Lake Mälaren in central-eastern Sweden.

The strait was of importance before Stockholm was founded in the 14th century, as it guarded the waterway to the significant Swedish medieval cities Uppsala and Sigtuna.

For instance, an attack on Sigtuna by Baltic Vikings in 1187 led to a battle at Almarestäket, resulting in the death of Archbishop Johannes.

There was a fortress built here in the mid-late 14th century, under the reign of Albert of Sweden.

Most of it was filled up in 1875 when the main line railroad (Västra Stambanan) was built in Sweden.