The Neckar River runs through Tübingen. With landfill, the city created a long and narrow island in the river's center. This island can be reached by walking across a wide bridge, called Eberhardsbrücke. Locals enjoy walking the tree-shaded promenade Platanenallee, which, in warm weather, is filled with strollers. From there, you get a panoramic view of the town, with its willows and houses reflected in the river. Towering above the other buildings is the Schloss Hohentübingen (Renaissance castle), which is now used by the university. It's worth climbing up to the castle for the dramatic view from the terraces.
The narrow streets of the Altstadt wind up and down the hillside, but they all seem to lead to Marktplatz, where festive markets are held on Monday, Wednesday, and Friday. You'll feel as if you're stepping into the past when you come upon country people selling fruit and vegetables in the open square. Facing the square is the Rathaus, which dates from the 15th century but also has more recent additions, including the 19th-century painted designs on the facade.
On a hillside above Marktplatz is Stiftskirche, Holzmarkt, the former church of the Stift, an Augustinian monastery. The monastery became a Protestant seminary in 1548, and its church became the Collegiate Church. Worth seeing inside are the tombs of the dukes of Württemberg in the chancel and the 15th-century French Gothic pulpit and rood screen. The church is open daily 9am to 5pm. You can climb the tower (enter on the left of the chancel) for a panoramic view. The chancel and tower are open Tuesday to Friday 10:30am to 5pm, and Saturday and Sunday 2 to 5pm. Admission to the tower is 2€ ($2.60) for adults and 1.50€ ($1.95) for children.
Hölderlinturm, Bursagasse 6 (tel. 07071/22040), lies at the end of a walk by the Neckar River. This was the home of the lyric poet Friedrich Hölderlin, who resided here with the Zimmer family from the onset of his mental illness at age 36 until his death in 1843, at age 73. Hölderlin is not well known outside Germany, but we highly recommend that you read a few of his poems in translation. Most tours of the museum are in German, but you can request one in English. The house is open Tuesday to Friday 10am to noon and 3 to 5pm, Saturday and Sunday 2 to 5pm. Admission is 1.55€ ($2) adults, 1€ ($1.30) students and children.