//
As the city has long been a major wine trading centre, large parts of it have extensive vaults underneath. Up to 120 meters (!) long and sometimes multi-storied, these vaults make for a fun excursion. Unfortunately, tours are rare, taking place only at the last Friday of each month. You need to reserve ahead, via the tourist office. For groups, separate tours can however be booked.
Constructed around the year 1350, the Grevenburg was originally the ancestral seat of the counts of Sponheim. Repeatedly besieged, damaged, occupied and rebuilt, it was conquered for the fourth and last time in 1734 by the French, during the War of the Polish Succession. The castle was blown up and large parts of it fell down into the river valley below. Only a few ruins are standing today, but much of the foundations remain. At the ruins, there's a small tavern and some gardens, and of course you get to enjoy some excellent panoramic views. The Mittelmosel-Museum has detailed documentation about the castle. It also provides further information about opening hours.