Löwenburg, Artificial ruin in Bad Wilhelmshöhe, Germany.

Löwenburg is an artificial castle ruin built from 1793 to 1801 on a wooded slope above Wilhelmshöhe Palace in Kassel's Bergpark. Its rough grey stone walls, Gothic arched windows, a tall thin spire, a round turret with a conical roof, a larger cylindrical tower and a square tower enclose a courtyard. The complex was designed by Heinrich Christoph Jussow as a complete hilltop castle, not a fragmentary ruin.

The castle was commissioned between 1793 and 1801 by Landgrave Wilhelm IX of Hesse-Kassel as part of the Bergpark Wilhelmshöhe landscape. It arose during a period when landowners built such structures as retreats and expressions of their artistic ideals.

The castle reflects the Romantic era's fascination with medieval forms, showing Gothic details that visitors can examine throughout the building. This deliberately designed ruin reveals how people of that time imagined and celebrated the past through architecture.

Visitors can explore the castle interior through guided tours that reveal period furniture, artifacts, and architectural details. The surrounding park provides walking paths for visitors to wander and experience the broader landscape at their own pace.

The keep was gutted by the air raid of 22 October 1943, leaving only the stair tower and fragments of wall; the castle thus returned to the ruined state its builders had staged. Rebuilt and reopened in July 2022, the tower now has a viewing platform about 25 metres up.