Tynnelsö Castle

Tynnelsö Castle is a stone fortress located on an island in Lake Mälaren, situated northeast of Strängnäs. The building features a square layout with multiple stories and appears as a solid fortified structure rising from the water.

Construction began in the 1490s under Bishop Kort Rogge, who built the first stone fortress on the island. The original ground floor structure remains intact and reflects the design from this early building phase.

The castle served as a strategic military fortification in 1443, housing 24 firearms, multiple cannons, and an arsenal of crossbows.

The castle is currently managed by the Swedish National Property Board and is undergoing extensive restoration work. Visitors should note that it remains closed during these repairs, though it can be viewed from the water or surrounding areas.

During Bishop Sigge's leadership from 1449 to 1463, the castle maintained a garrison of 100 men, making it one of Sweden's strongest fortifications.

Location: Strängnäs Municipality

Inception: 13 century

Operator: Statens Fastighetsverk

Website: https://sfv.se/fastigheter/sok/sverige/sodermanlands-lan/tynnelso-slott

GPS coordinates: 59.41222,17.10028

Latest update: December 8, 2025 21:02