Mendoza  makes a great walker’s city; to get the lay of the town, take the elevator to the rooftop Terraza Mirador at the Municipalidad (9 de Julio 500, tel. 0261/4296500), two blocks south of Plaza España. Hours are 8:30 a.m.–1:30 p.m. and 5–8 p.m. weekdays, 10 a.m.–1 p.m. weekends.
The best place to start a walk, though, is the broad Plaza Independencia, bounded by Espejo, Chile, Rivadavia, and Patricias Mendocinas. Crossed by diagonal, perpendicular, and curving pathways, embellished by trees and fountains, it’s a major site for civic events, outdoor concerts, and a weekend crafts fair. It also features the subterranean Teatro Quintanilla and the contemporary Museo Municipal de Arte Moderno (tel. 0261/425-7279, 9 a.m.–8 p.m. Tues.–Sun., US$1, free Wed.).
Immediately east of Plaza Independencia, under a forest-dense canopy, the pedestrian Paseo Sarmiento is home to the Legislatura Provincial (provincial legislature), detailed in Argentina’s national colors of celeste (sky blue) and white. Sarmiento’s sidewalk cafés and benches make it ideal for people-watching; take a detour into the vitraux-studded galleries of its Pasaje San Martín.
Two blocks south of Sarmiento, Plaza España’s intricate tile work makes it the city’s most interesting; four blocks west, Plaza Italia honors the city’s Italian community.
Four blocks north of Plaza Italia, rehabbed Plaza Chile honors Argentina’s western neighbor. Once part of colonial Chile, Cuyo  feels closer to the adjacent republic than any other part of Argentina—so close that, since the 2002 devaluation, Mendoza  officials have encouraged Chileans to celebrate Chile’s September patriotic holidays here.
One block north of Plaza Chile, on Avenida Las Heras between Avenida Perú and 25 de Mayo, the inventive Museo Popular Callejero is a series of historical dioramas in metal and glass cases on the sidewalk. They depict typical activities on what was once a dry streambed but became one of Mendoza’s major shopping streets.
Four blocks west of Plaza Chile, Plaza San Martín aspires to honor Argentina’s icon but wallows in hero worship. At its northwest corner, dating from 1875, the Basílica de San Francisco (Necochea and España) is the oldest church in the new city. It holds the image of Nuestra Señora del Carmen de Cuyo, the patron of San Martín’s army, while its mausoleum is the final resting place of the Liberator’s daughter, son-in-law, and granddaughter (the patriarch himself remains in Buenos Aires ).
To the north, the Museo Histórico General San Martín (Remedios Escalada de San Martín 1843, tel. 0261/425-7947, 9:30 a.m.–1 p.m. and 3:30–7 p.m. Mon.–Fri., 9:30 a.m.–1 p.m. Sat., US$1.25) is a kitchen-sink clutter of sanmartiniana that still needs a professional makeover.
Seven blocks east of Plaza San Martín, the south end of Parque Bernardo O’Higgins holds the Acuario Municipal (Ituzaingó and Buenos Aires, tel. 0261/425-3824, 7 a.m.–7 p.m. daily, US$1). The municipal aquarium has small tanks with mostly small to midsized subtropical and tropical species, primarily from the Río Paraná but also elsewhere in the Americas along with a few from Asia and Africa. The standout exception is an enormous loggerhead turtle named Jorge, caught off Bahía Blanca in 1985, but not returned to the ocean because of an injury.
At the park’s north end, the so-called Ruinas de San Francisco are the seismic remains of a 17th-century Jesuit church and school, but the Franciscans claimed the site after the Jesuits’ 1767 expulsion from the Americas.