pfalzgrafenstein castle which used to serve as a customs checkpoint on river rhein near kaub, germany

rhine pfalzgrafenstein castle river germany kaub world heritage unesco island architecture falkenau landmark shore landscape pfalz tower town customs german vineyard gutenfels valley church medieval hilltop rhinelandpalatinate burg outdoors travel rhein tourism rheingau hesse tourist wine bank riverbank summer mountain historic hessen rheinlandpfalz countryside day hill cruise riverside palace water