The Altrhein

From April to October, you can take a short river cruise through the network of branching arms of the river to the north or south of Speyer to discover the idyllic landscape of the ancient, forested islands along the Altrhein, the original course of the Rhine. The islands are home to rare flora, fauna, and many birds; and there are grand views of the cathedral from the boat.

Fahrgastschifffahrt Speyer. From March to November, boat tours depart from just outside the Sea Life Aquarium at noon, 2, and 4. The trip lasts about 1½ hours and offers a unique look at Speyer's old harbor and its fascinating network of rivers. Hafenstr. 22, Speyer, Rheinland-Pfalz, 67346. 06232/291–150; www.ms-sealife.de. €10.

Pfälzerland Fahrgastschiff. Enjoy a peaceful tour of the Speyer harbor and its surrounding river network on a ship built for 200 passengers. Homemade cakes and drinks are available on board. Tuesday through Friday, 1½-hour tours depart at 1 and 3, on Saturday at 1:30, 3, and 5 and on Sunday at 1, 3, and 5. The pickup and drop-off point is on the Leinpfad. Dock: Leinpfad [via Rheinallee], on the Rhine riverbank, Rheinalle 2, Speyer, Rheinland-Pfalz, 67346. 06232/71366; www.personenschifffahrt-streib.de. €10.