Located directly at the Rhine in the middle between Mainz and Worms, Oppenheim was granted market rights in 1008, city rights in 1225 and flourished until overrun by Spanish, Swedish and French troops in 1620, 1631 and 1689 respectively. After that it never regained its previous importance and wealth, but remains a charming small city with medieval flair, proud of its history and its wine. Particularly the Krötenbrunnen vineyards are sometimes known beyond Germany.
Oppenheim once was home to a small Jewish community, which was scattered by the atrocities before and during WWII. Several families named 'Oppenheimer' can be found in the USA and other parts of the world.
Fast trains (ICE, IC, RE) won't stop in Oppenheim. Visitors have to take the slow train (RB, Regionalbahn). 'RB44' runs from Mainz via Oppenheim and Worms to Mannheim (or vice versa) every half an hour during normal hours on work days and once per hour on weekends. If you're coming in from nearby Frankfurt airport then take a train to Mainz first and change there.
From Oppenheim's train station it is only a 5-10 minutes walk to the Old Town. (There is a city map across the street from the station building.)
Saint Catherine’s Church (Katharinenkirche, built 1220-1439), often named 'the most outstanding Gothic church on the Rhine between Cologne and Strasbourg'. Most of the stained glass windows are still genuine from the 14th(?) century. Sometimes the church's main tower is open for visitors. If you get a chance, do climb it. The effort of the many stairs is rewarded by a spectacular view of the city.
The Ossuary (Beinhaus) immediately behind the church. Bones of 20.000 people neatly stacked are a creepy view ...
The Old Town with its marketplace and the Town Hall, just below the church.
St Bartholomäus Church, a bit south of the marketplace.
The ruin of Landskrone Castle, built in the 16th century on the remains of an even older (11th century?) castle, destroyed in 1689. Located at the very top you can get a great view of the city and the surrounding countryside. During summer the ruin is sometimes used for theater performances. If you walk from the ruin past the Ruprechtsturm downstairs to the Clock Tower (Uhrturm, near the train station) you might notice a huge chunk of curved brickwork. This is a piece of the castle's round main tower. Despite weighing several tons, it was hurled several hundred meters when the tower was blown up in 1689.
The Gautor, a gate building in the city's old fortifications, about 100 m south-west of the marketplace.
The Oppenheimer Kellerlabyrinth (Oppenheim Cellar Maze) under the Old Town, sometimes also called Stadt unter der Stadt (City beneath the city). Spurred by the city's uneasy past and the soft yet sustainable soil, Oppenheim's medieval inhabitants dug at least 40 km worth of tunnels and rooms beneath the 'visible' city. Among other things, the St Catherine's Church's stained glass windows survived here not only several medieval wars but also WWII bombings. A part of the tunnels have been made accessible to the public. Guided tours (in several languages) are offered by the town’s tourism and festival play bureau (Merianstr. 4, near the marketplace at the street leading up to St Catherine's).
Town Museum (also Merianstr. 4).
German Viticultural Museum (Deutsches Weinbaumuseum, Wormser Str. 49, tickets 3 €), showing (old) methods and tools for wine production.