Most of Porto Alegre [1]’s most interesting attractions are located within the old city center (Centro) next to the river, a compact region easily explored on foot. Although a late-20th-century building boom resulted in a sea of nondescript office towers and busy thoroughfares, a significant number of grand neoclassical buildings happily survived the wrecking ball.
Walking around the Centro is safe enough during the day, but be careful at night (take a cab) when businesses close and the area becomes more deserted.
For city tours, the Linha Turismo (Travessa do Carmo 84, Cidade Baixa [2], tel. 51/3212-3464, 9 a.m., 10:30 a.m., 1:30 p.m., 3 p.m., and 4:30 p.m. Tues.–Sun., R$8–10) is a double-decker bus that visits 17 tourist sites.
To view Porto from the Rio Guaíba, two boats—the Cisne Branco (departing from the port at Av. Mauá 1050, tel. 51/3224-5222, www.barcocisnebranco.com.br [3], Tues.–Sun., R$15), and the more rustic Noiva do Caí (departing from the Usina do Gasômetro, tel. 51/3211-5222, R$7), offer several outings a day, lasting an hour.
Links:
[1] http://www.moon.com/destinations/brazil/the-south/rio-grande-do-sul/porto-alegre
[2] http://www.moon.com/destinations/brazil/bahia/salvador/sights/cidade-baixa
[3] http://www.barcocisnebranco.com.br