Blocksberg, Medieval castle in Ratekau, Germany.

Blocksberg, also called Pansdorfer Schanze, is a protected earthen ring wall near Pansdorf in the municipality of Ratekau. The irregular ring measures roughly 110 to 120 metres across and stands 5 to 8 metres high, dropping up to 20 metres into the surrounding lowland. It is a Wendish fortification of the 8th and 9th centuries, not a stone castle.

The Blocksberg is a Slavic ring wall from the 8th and 9th centuries, built on the fortified northern part of a glacial ridge. The site was protected by the Schwartau river to the west, a deep stream valley to the north and marshy ground to the east; to the south, a ditch and rampart cut it off from the rest of the ridge. A possible outer bailey, called Ohlborg, lay on a ridge to the south.

The name Blocksberg is a later German label; locally the site is also called Pansdorfer Schanze, and the forested ridge just south is known as Ohlborg, possibly the location of a forecourt. The rampart itself is an earthen ring wall of the 8th and 9th centuries, not a stone castle, so visitors see grass-covered banks and ditches rather than masonry.

The wall sits on the fortified northern part of a ridge, enclosed by the Schwartau to the west, a deep stream valley to the north and marshy ground to the east; a ditch and rampart cut it off to the south. Approach from Pansdorf and expect uneven ground on the slopes, which fall up to 20 metres into the lowland.

Ancient circular ramparts remain visible at the site, showing the original defensive system and inviting a walk along the old defensive line. These ring-shaped structures give visitors a direct impression of how the terrain was once protected.