Abbey governor's office with castle tower and moat, Water castle in Freienbach, Switzerland

Pfäffikon Castle, formerly Weissenburg, is a water castle near Lake Zurich in Pfäffikon. Its square main tower measures 12.3 m per side and 13 m high, with walls 2.3 m thick at the base tapering to 1.4 m. The Gothic chapel has a rectangular nave and polygonal choir, with Neo-classical stucco and mahogany altars by Father Rudolf Blättler (1892).

Originally built as a storage granary for Einsiedeln Abbey in the 13th century, the site received walls and fortifications later, particularly following disputes over grazing rights in 1299. These additions secured its role as a fortified administrative base for subsequent centuries.

The complex demonstrates how religious and administrative power merged in one place, serving as both an abbey governor's residence and a fortified stronghold. The buildings still express this dual purpose and shape how visitors experience the site.

The tower stands in the Unterdorf of Pfäffikon, close to Lake Zurich, and is reached on foot from the village lanes; the moat that once ringed it survives only as the main moat. The tower, chapel and former governor's residence are separate parts of one site, and the residential wings now house municipal offices, so some areas are not open to visitors.

During an uprising in 1314, the castle protected important Abbey documents when attackers tried to destroy land and tax records. This role as a vault for valuable records shows how much the fortification was trusted as a secure storage place.