Resting at the foot of dramatic slopes along the Rhine Gorge, a UNESCO World Heritage Site, the sleepy town of Sankt Goar is overseen by the famous 13th-century ruins of Rheinfels Castle. The largest castle on the Rhine, its ruins have been partially restored and some of its buildings today host a luxury hotel and wellness center. Sankt Goar was named for a 7th-century priest, hermit and later saint who was known for performing miracles. On the river’s opposite bank, the smaller yet no less splendid castles of Katz and Maus (“Cat” and “Mouse”) also enjoy lofty perches.