Nights here are alive with the youthful enthusiasm of Heidelberg's students. Early evenings often start in the bars along Hauptstrasse; then late nights get rolling in the clubs around Marktplatz.

The Performing Arts -- The main performance stage is Theater der Stadt, Friedrichstrasse 5 (tel. 06221/58-35-02; bus: 41 or 42), where nightly entertainment includes plays, opera, and dance productions. For 5 weeks beginning in late July, the Schlossfest-Spiele festival brings opera, classical music, jazz, and theater to venues around the area, including Heidelberg Castle. Contact tel. 06274/-582-000 for tickets.

Historic Student Drinking Clubs -- Heidelberg's most famous and revered student tavern, Zum Roten Ochsen (Red Ox Inn), Hauptstrasse 217 (tel. 06221/2-09-77; bus: 33), opened in 1703. For six generations, it has been in the Spengel family; they have welcomed everybody from Bismarck to Mark Twain. It seems that every student who has attended the university has left his or her mark (or initials) on the walls. The series of rooms, where revelers sit at long oak tables under smoke-blackened ceilings, is arranged in horseshoe fashion; the U part has a pianist who sets the musical pace. As the evening progresses, the songs become louder and louder. Motherly looking waitresses bring in huge steins of beer and plates of food. A mug of beer costs 2.40€ and up, wine is 6.50€ per glass. Meals go from 8.90€ to 18€. The tavern is open Monday through Saturday from 11:30am to 2pm and 5 to 11:30pm (sometimes to midnight). Closed mid-December to mid-January.

Next door is Zum Sepp'l, open since 1634, Hauptstrasse 213 (tel. 06221/2-30-85; bus: 11 or 33), the second most famous drinking club in Heidelberg. It's also filled with photographs and carved initials of former students, along with memorabilia that range from old Berlin street signs to Alabama license plates. The building itself dates from 1634. Meals cost 5.80€ to 13€. A mug of beer goes for 2.40€. There's live piano music Monday, Tuesday, Friday and Saturday from 8pm to midnight. When the university is closed, the activity here dies down considerably. It's open Monday to Friday 5pm to midnight and Saturday and Sunday 11:30 am to 3:30pm and 5pm to midnight.

Bars & Cafes -- Max Bar, Marktplatz 5 (tel. 06221/2-44-19; bus: 11 or 33), is a beer-drinker's bar, but you can also get a baguette or croissant to soak up some of the alcohol. There's indoor and patio seating. Open daily 8am to 1am. When you tire of beer and want a more spirited drink, wander over to Sonder Bar, Unterestrasse 13 (tel. 06221/2-52-00; bus: 41 or 42), which stocks more than 150 brands of whiskey, 10 kinds of vodka, and sundry other potions, besides its 11 types of beers. Open daily 2pm to 2am.

Catch up on the latest news and trends at Café Journal, Hauptstrasse 162 (tel. 06221/16-17-12; bus: 41 or 42), where drinkers linger over beer while scanning newspapers and magazines from all over Europe and the United States. Open daily 8am to 1am. Hard Rock Cafe, Hauptstrasse 142 (tel. 06221/2-28-19; bus: 41 or 42), has a branch here, open 10am to 1am. A popular bar with a mixed gay crowd, Mata Hari, Oberbadgasse 10 (tel. 06221/18-18-08; bus: 11 or 33), is a mellow place to meet and drink. Open 8pm to 3am nightly.

Live Music & Clubs -- The Schwimmbad Musik Club, Tiergartenstrasse 13 (tel. 06221/47-02-01; bus: 33), features trend-setting local and international bands, and is open Wednesday and Thursday 8pm to 3am, Friday and Saturday 8pm to 4am. Cover ranges from 1.50€ to 11€.

Named after a barbecue sauce from Texas, Ziegler-Bräu/Billy Blue's, Bergheimer Strasse 1B (tel. 06221/2-53-33; tram: 1 or 5), serves up barbecue in the front room while local and international bands play soul, funk, and blues in the back Wednesday to Saturday nights. Open daily 5pm to 3am; cover is 4€ on Wednesday or 3€ on weekends (otherwise free).

One of the oldest jazz clubs in Germany, Cave 54 Krämergasse 2 (tel. 06221/278-40; bus: 11 or 33), is a perennial favorite. It offers live jazz every Sunday, with other nights devoted to soul, funk, and reggae. Open daily 9pm to 3am, cover is 3€ Tuesday night and 6.50€ on Sunday (otherwise free).