Château de Kaysersberg

Château de Kaysersberg, also known locally as the Schlossberg, is a ruined medieval castle perched on a hill above Kaysersberg-Vignoble, a well-preserved wine-country town in the Haut-Rhin département of Alsace. From its walls, visitors look down over the old town's rooftops, the vineyard slopes surrounding it, and the valley of the Weiss river.

Who built the castle, and when?

Construction began around 1227 under Albin Woelflin, an imperial bailiff acting on behalf of Emperor Frederick II of Hohenstaufen in Alsace. Frederick II was the grandson of the more famous Frederick Barbarossa, and it is actually Barbarossa's name that survives in local legend as the builder of a hidden treasure supposedly buried within the castle — though the fortress itself was raised a generation later, under his grandson. The site was chosen to secure a key route linking Lorraine and Alsace, giving the empire control over an important trade and military corridor. Shortly after the castle went up, the town below was fortified as well, and its ramparts were joined to the castle between roughly 1264 and 1268, forming a single defensive system.

What does the keep look like?

The heart of the fortress is a circular keep dating from the same building phase, around 1227. It stands about 22 metres tall with a diameter of roughly 11.4 metres, and its walls reach up to 4 metres thick — so thick that the interior leaves barely enough space for a staircase winding up to the top. That mass of stone made the tower extremely resistant to siege and very difficult to storm directly.

Why did the castle fall into ruin?

Decline set in well before the modern era: by around 1600, records already describe the castle as dilapidated. The Thirty Years' War (1618–1648) delivered the final blow, leaving the structure damaged and permanently uninhabitable once the fighting ended. In 1796, during the revolutionary period, it was sold off as national property, and its new owners tore down the remaining residential buildings to plant vineyards on the cleared land — vines that still grow at the foot of the walls today. Further damage came from treasure hunters chasing the legend of Barbarossa's hoard: over the following centuries they dug wildly through the ruins, at times even using explosives, which seriously weakened what was left of the walls.

Can visitors explore the castle today?

Yes. A major restoration campaign in 1955 stabilised the ramparts and the keep, making the ruins safe to visit. Access is free and unrestricted, and a short, fairly steep path leads up from the centre of Kaysersberg-Vignoble to the base of the tower. It remains a popular walk that combines a dose of medieval history with sweeping views over Alsace's vineyard landscape.

Frequently asked questions

Where does the name Kaysersberg come from? It translates literally as "the emperor's mountain" (German Kaiser, "emperor," and Berg, "mountain"), a direct reference to the castle's imperial origins and its role guarding Holy Roman Empire authority in the region.

Is there an entrance fee? No, the ruins are open to the public free of charge year-round, though the climb up is steep in places.

What else is worth seeing nearby? Kaysersberg-Vignoble itself is known for its half-timbered Alsatian architecture, its surrounding vineyards, and as the birthplace of Nobel Peace Prize laureate Albert Schweitzer.

Does the castle offer a view over the town? Yes, the castle hill is a natural viewpoint over the old town, the Weiss river, and the terraced vineyards that climb the valley around it.