Stegeborg Castle

Stegeborg Castle is a medieval fortress ruin located on an island in Slätbaken bay, featuring a square brick tower in the southeast corner and a round tower in the west connected by defensive walls. The remains reveal the layout of a strategic stronghold built to control passage through the sound.

Built in the early 13th century, the fortress was expanded in the 16th century under King John III of Sweden with additional fortifications. These additions reflect the ongoing importance of controlling waterways in the region.

The name comes from "stæk," referring to wooden poles that were placed in water to manage ship traffic through the narrow sound. Today, visitors can still sense how this location controlled the movement of vessels through an important maritime passage.

The ruins stand on an island in Slätbaken bay, requiring planning to reach them safely depending on tidal conditions. The location allows visitors to observe both the stone structures and remnants of the underwater defensive system from the shore.

The fortress used a sophisticated defense system with submerged wooden pilings that could block ships, remains of which are still visible underwater today. This submerged component makes the castle a rare example where both above-ground and underwater medieval military engineering can be studied.

Location: Söderköping Municipality

Website: http://stegeborg.se/slottsruin.php

GPS coordinates: 58.44156,16.59814

Latest update: December 7, 2025 20:45