Weissenau Castle was first mentioned in the historic record as castrum Wissenowe in 1298. It is unclear whether it was built by the Lords of Rotenfluh (Unspunnen) and then given in fief to the Freiherr of Weissenau or if it was built by the Weissenau family as the center of their estates. The castle was built on what was an island at the mouth of the Aare river into Lake Thun. In the intervening centuries, the waterway silted up and the island became connected to shore. The market town of Widen grew up across the channel from the castle and in 1362 was connected to the castle by a bridge. Around 1334, the Freiherr of Weissenau joined other local nobles in a war against the growing power of the city of Bern. After the defeat of the nobles, Weissenau was forced to sell the castle and Widen to Interlaken Abbey to pay his debts. In 1365, the Abbey moved the weekly markets and yearly fair away from Widen and to the village of Aarmühle (which is now Interlaken). Losing the market devastated Widen and it began to decline.
In 1528, the city of Bern adopted the new faith of the Protestant Reformation and began imposing it on the Bernese Oberland. The Abbey and its villages joined in an unsuccessful rebellion against the new faith. After Bern imposed its will on the Oberland, they secularized the Abbey and annexed all the Abbey lands. Weissenau Castle and the small village of Widen became a part of the Bernese bailiwick of Interlaken. The castle was used as a prison into the 16th century, but began to fall into disrepair and eventually collapsed. In 1655 and again in 1700 the bailiwick made plans to renovate and repair the castle. However, neither plan was implemented.
Today only ruins remain of the castle. The castle residence and tower, portions of the castle building and the curtain wall are all still standing.
References:The Pilgrimage Church of Wies (Wieskirche) is an oval rococo church, designed in the late 1740s by Dominikus Zimmermann. It is located in the foothills of the Alps in the municipality of Steingaden.
The sanctuary of Wies is a pilgrimage church extraordinarily well-preserved in the beautiful setting of an Alpine valley, and is a perfect masterpiece of Rococo art and creative genius, as well as an exceptional testimony to a civilization that has disappeared.
The hamlet of Wies, in 1738, is said to have been the setting of a miracle in which tears were seen on a simple wooden figure of Christ mounted on a column that was no longer venerated by the Premonstratensian monks of the Abbey. A wooden chapel constructed in the fields housed the miraculous statue for some time. However, pilgrims from Germany, Austria, Bohemia, and even Italy became so numerous that the Abbot of the Premonstratensians of Steingaden decided to construct a splendid sanctuary.