One of the oldest towns in Germany, the former Roman settlement on the Rhine is famous for its mighty landmark Speyer Cathedral, an UNESCO World Heritage Site that is the largest Romanesque church in Europe.
Speyer is also noted for its Jewish heritage and the mikveh, the traditional bathhouse, which was built in 1128; it's included in most guided walking tours. Other attractions include the Old City Gate dating to the 13th century, Sea Life center with more than 3,000 marine creatures housed in 40 displays and a wide pedestrian-only shopping street -- directly opposite the cathedral -- with restaurants, cafes and shops selling souvenirs and authentic German clothing.
From the docking point for river ships, it's a pleasant 10- to 15-minute walk through a leafy park to the cathedral and town center. The large Alter Hammer beer garden, overlooking the river, is a lovely spot to stop for a drink on the way back to the ship; just watch the time as stops in Speyer are generally only a few hours.