Pfalzgrafenstein Castle, also known as the Pfalz, is a toll castle located next to Kaub, Germany, on the island of Falkenau in the Rhine River. When King Ludwig IV of Bavaria first built the castle in 1326–1327, it was used to collect river tolls from passing traffic. It saw military action as well; in the War of the Succession of Landshut in 1504, it withstood a 39-day siege, and starting in 1620, Spanish forces controlled it for 11 years. Since its original construction, the castle has under ... (Read More)