Fornborgar på Öland - 5 castles you don't want to miss!

Writer: Helena Bergström

Updated: October 2026 | Did you know that there are about fifteen ancient castles from the Iron Age on Öland? The castles are today ruins that tell the story of life in the Iron Age, long-distance contacts, wealth – and sudden death through archaeological findings. One of them, Eketorp Castle, has been excavated and reconstructed so that you can get a picture of what life may have once been like.

Fornborgar on Öland

At first glance, the ancient cities of Öland may seem like just ruins of stone and earth, but they have a lot to tell. Finds of Roman gold coins, among other things, testify to wealth and long-distance contacts during the Iron Age.

We have visited five of the ancient castles on Öland, which we tell you more about. Here you can see where they are located.

1. Eketorp Castle - a reconstructed Iron Age castle

Eketorp's castle is the only one of Öland's ancient castles that has been recreated so that you can get a visual picture of what life was once like here. There were buildings inside the castle between the 3rd and 13th centuries, and today the rebuilt castle is a major attraction.

Given the large car park and the modern tourist centre, it can be quite busy at times. We happened to come here on a day when the visitor centre and museum house were closed, but it was still possible to visit the castle itself.

In the inner courtyard, several dwellings have been built, so you can see what it might have looked like in the past. Signs with text and pictures contribute even more to the picture that emerges. During the season, various activities are arranged that bring life to life during the Iron Age and the Middle Ages. Check the current program and opening hours before your visit.

2. Bårby Castle - with gold coins from Rome

Bårby Castle is located in the south-west of Öland. This castle was built between 400 and 700 AD. In this castle, as in many other Öland castles, the buildings were carefully planned. The houses had common walls and were built almost as terraced houses.

Inside the castle, a farmer found a gold coin from Eastern Europe in the early 1900s. However, to imagine what once was requires a large dose of imagination. The only thing visible today is the circular rampart.

3. Sandby village - the massacre that stopped time

Sandby Castle is not the most spectacular of Öland's ancient castles in terms of visual appearance – today, all that is visible are parts of the demolished wall. But the history is all the more fascinating. We went here after reading about the castle, and it is actually the history of this particular place that we remember most strongly afterwards.

In 2010, a series of 4th century jewellery caches were found here, with exclusive glass beads, rings and gilded costume buckles. When excavations began, a terrible story emerged. Everywhere in the castle, human remains were found, all over the place.

Everyone seems to have been killed by force, and no one seems to have been left behind to bury the dead. In the picture below you can see an overview of the people found in house 40 - ranging from children to adults. The photos below were taken at an exhibition about the castle at the Kalmar County Museum in Kalmar, Sweden. squid. You can also read about different theories about what might have happened, very interesting!

READ MORE: Kalmar County Museum – interesting exhibitions

4. Gråborg - Öland's largest ancient castle

Of all the ancient fortresses on Öland, Gråborg, located in Borgs village in central Öland, was by far the largest. Roman gold coins (solidus) have been found here, indicating both wealth and a time of travelling and contacts across the world.

When the castle was built in the 3rd century, it was an impressive structure that could be seen from afar. Like Ismantorp Castle (below), it was equipped with nine openings in the wall - perhaps to symbolise the nine worlds of Norse mythology. Gråborg is one of around five ancient castles that were rebuilt in the 12th century, and is therefore better preserved than many others.

In Borg village, in addition to Gråborg, you can visit the ruins of St Knut's chapel. The chapel was built in the late 12th century and abandoned in the early 16th century.

5. Ismantorp fortress - with inspiration from ancient Norse mythology

Ismantorp Castle is an exciting place in the middle of the Mittlandsskogen forest on central Öland. After a short walk through the greenery, you arrive at the large ring castle – a place that is still something of an archaeological mystery.

The castle is 127 meters in diameter and is surrounded by a 3–4 meter high wall with nine gates. Inside the wall are 88 house foundations, which are still clearly visible above ground. Archaeological investigations have not yielded any findings that can definitely date the castle, and the exact function of the site is still debated.

We found Ismantorp Castle to be a fascinating place. There are no reconstructed houses here like at Eketorp – instead, the ruins, the forest and the imagination are left to do the work.

More ancient castles on Öland

For those who are particularly interested, there are even more ancient castles on Öland to discover. We think we found some of the most interesting ones - and can definitely recommend a combination with the exhibition about Sandby Borg at Kalmar County Museum.

Visit to Öland's ancient castle

We managed to visit five of Öland's ancient castles and they provided very different experiences. Eketorp is best if you want to get a concrete picture of what a castle might have looked like, Gråborg impresses with its size and Ismantorp with its environment and the clear foundations of the buildings. Sandby Castle perhaps made the strongest impression on us – not through what you see, but through its dramatic history.

See more on Öland

• Coastal road Byrum-Äleklinta
• Fornborgar on Öland
• Around Öland by car or campervan
• Things to do on Öland