To be privately owned
Burg Castle

Schloss Burg stands on a rocky spur above the village of Burg in the canton of Basel-Landschaft, Switzerland. Its structure dominates the landscape and dates back to the 13th century.
History+
The exact origins of Schloss Burg are not fully clear, but the oldest surviving structural elements date from the mid-13th century. It is believed that a mention of Burg Biederthal in the 12th century refers to another ruin nearby. Around 1250, the current complex, then also called Burg Biederthal, was built under the Lords of Biederthal from the House of Ratolsdorf, who held the property as a Habsburg possession. In 1269, the castle passed into the possession of the Bishop of Basel.
Source: Wikipedia · Licence: CC BY-SA 4.0
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 47.4567, 7.4406