There’s no doubt about it: Puerto Ricans love a good party, and it seems as if there’s always one going on somewhere. San Juan has a couple of unofficial party districts where the concentration of bars and restaurants creates a street-party atmosphere that attracts young locals and tourists alike to barhop and people-watch. Although generally safe and contained, these areas can experience a certain level of rowdiness and petty crime, particularly when heavy drinking is involved. Visitors are encouraged to have a good time, but they should take care to keep their wits about them.

One popular party spot just a short taxi ride from Condado is Plaza del Mercado (Calle Roberts in Santurce), a small grid of narrow streets that surround Santurce’s historic marketplace. The area contains a high concentration of tiny bars and restaurants serving cheap drinks and local cuisine. The streets get especially crowded Thursday, Friday, and Saturday nights with locals celebrating the weekend.

If the walk-up bars and street scene get to be too much, duck into Buyé Bistro Criolla (202 Calle Canals, by Plaza del Mercado, Santurce, 787/725-4826, Mon.–Wed. 1–3 p.m., Thurs.–Fri. 1–3 p.m. and 5 p.m.–1 a.m., Sat. 5 p.m.–1 a.m.), especially on a Friday night. DJs spin here until the wee hours of the morning at this casual bar and restaurant. Check the chalkboard for daily specials ($7.95–16.95).

Another popular party district is Boca de Cangrejas (end of Ave. Isla Verde, just past the airport), a sandy patch of beachfront bars, restaurants, clubs, and food kiosks. Since this is also a popular weekend beach spot, the party tends to start early here, but the fun still lasts late into the night. The best way to get to Boca de Cangrejas is to drive or take a taxi, although you’ll have to call one to pick you up when you’re ready to leave. If you drive, be sure not to leave anything of value visible in the car; break-ins are not uncommon.

Although most establishments are open-air concrete structures, there are a few more-upscale places, such as Soleil Beach Club (Carr. 187, km 4.6, 787/253-1033, www.soleilbeachclub.com, Sun.–Thurs. 11 a.m.–11 p.m., Fri.–Sat. 11 a.m.–2 a.m.), near Boca de Cangrejas in Piñones. The beachside establishment with the palm-frond entrance serves Puerto Rican cuisine and offers live Latin music.

In Old San Juan, party central is along Calle San Sebastían. Bars, clubs, and pool halls of every stripe line the street, making it a great place to barhop door-to-door. Standard stops include Nono’s (109 Calle San Sebastían, 787/725-7819, daily noon–2 a.m.) and Cafe San Sebastían (153 Calle San Sebastían, 787/725-3998, Wed.–Sun. 8 p.m.–3 a.m.).