The Argentinean capital of Buenos Aires is known for its elegant shopping boulevards, lively artist quarter and beautiful parks. Among the most important sites are the National Art Museum, the Historical Museum and the magnificent opera house Teatro Colón. The sightseeing highlights include the mighty 18th century cathedral, the charming narrow streets of the old town and the Plaza de Mayo. Every Thursday, the mothers of those who disappeared during the military dictatorship still hold their solemn vigil on the Plaza de Mayo. The Casa Rosada, the pink presidents' palace and the former city hall are located beyond the square. Most of the residents of La Boca, one of the oldest city quarters, are descendants of Italian immigrants. In San Telmo, the artist quarter of Buenos Aires, there are still many buildings from colonial days. Cafés and a friendly atmosphere are part of the street scene here, along with the weekend antique market. Well maintained parks are located everywhere in the city, inviting visitors to take long, leisurely strolls. The Botanical Gardens and the Zoo are also worth visiting.