Burg Rettenberg

Burg Rettenberg stands on a narrow ridge above the Iller valley in the Allgäu uplands. The ruins crown a flat limestone crag about 30 metres square, 300 metres above the valley floor. The site commands sweeping views north over the Rottachberg massif and south into the Tirolean Außerfern. A waymarked path from Vorderburg climbs in twenty minutes; the route from the Rottachmühle in the valley takes just under an hour.

The castle was built around 1100 by the lords of Rettenberg, a Swabian family that rose from ministerial service to the Welfs and later to the Staufer. By the 12th century they controlled the vogteys of several monasteries and founded cadet lines such as the Trauchburg and Hohenegg. After Heinrich von Rettenberg died without heirs in 1350, his lands were split and sold for modest sums to the bishopric of Augsburg. The bishop’s officials occupied the keep until a fire in 1562 gutted the main building. Repairs were half-hearted, and by 1735 the administration had moved to Vorderburg.

Today only two high, crumbling curtain walls remain of the once-mighty tower castle. The southern curtain, fifteen metres long and windowless, faces the old approach; the western wall, nine metres long, still shows window openings. The inner face of the masonry rises in places to nine metres, built of Nagelfluh blocks quarried nearby. Below the plateau a small outer ward once stood, but no traces survive above ground. The exposed rock edges warn of falling stones, and the ruin is not yet part of the Allgäu castles trail.