Stegeborg's castle ruin was one of Sweden's most important strongholds during the Middle Ages and the ruin is located on a small island near the Göta Canal. You can go here every day of the week all year round. You pay for the entrance to a vending machine outside and then you can stroll around. We have visited Stegeborgs Slottsruin both summer and winter and it is as beautiful in the winter as it is in full bloom. The ruin is unmanned. Outside the castle is a harbor tavern which is open during the summer season and if you want to have a coffee or simple lunch there is the Garden Café which is open every day between 12:00 - 16:00 from 4 July - 2 August.