Toppler Castle

"Toppler Castle was built in 1388 and is even open for tours. Walk through the gate, ring the bell, and for 5€ a person the owner (who lives in the house next door) and her cat will take you on a private tour of this historical little building. One random site listed the hours as Fri-Sun from 1-4pm. There will be a sign on the gate that says either “heute geöffnet” (open today) or “heute geschlossen” (closed today). There is a phone number listed on the closed sign though – so you can call and ask when she will be available, if you speak German. If not, ask someone at your hotel if they would be willing to call for you."