This very full 1-day tour takes in the best of historic Buenos Aires, and its neighborhoods Monserrat and Retiro, giving you a taste of its beginnings and recent past as one of the world’s wealthiest cities: its European-influenced architecture, old-world cafes, and wide avenues, squares, and parks. You’ll need walking shoes. 
1. Casa Rosada
Americans have their White House, Argentines their Pink House. Erected in 1885, the presidential palace with the distinctive hue is where Eva Perón (1919–1952) addressed her adoring masses (though not from the front balcony, but from one on the south side, at Balcarce). 
2. Plaza de Mayo
The heart of the historic Monserrat district—and indeed, the entire city—this is the spot where Buenos Aires had its second founding in 1580. The square has been ground zero for virtually every momentous political event in Argentina’s modern political history, from presidential proclamations to mass protests by Perón’s blue-collar workers (the descamisados, or shirtless ones) to mournful demonstrations by the Mothers of the Disappeared, whose children were kidnapped and murdered by the military governments of the 1970s and early 1980s. Today, there are still frequent protests and occasional Thursday-afternoon appearances by the aging madres (mothers)—whose “ownership” of the plaza is marked by paintings of their symbolic headscarves on the tiles around the 1811 obelisk in the center. 
3. Catedral Metropolitana
Over the centuries, beginning in 1622, a half-dozen churches have occupied this spot. The present cathedral’s long construction period, from 1745 to 1836, is reflected in its inconsistent appearance, with an austere neoclassical exterior fronting a gilded, baroque interior. A mausoleum inside contains the remains of General José de San Martín (1778–1850), the national hero and “father of the nation” known as El Libertador for his campaigns to free the southern nations of South America from Spanish rule. 
4. Cabildo
The blindingly white old town hall rests on the spot where the town council first met at the end of the 16th century, and where Argentine independence took root during the May Revolution of 1810. It is the only public building on the Plaza de Mayo remaining from colonial days, and inside is a moderately interesting museum of colonial paintings and furniture. It’s worth a quick look inside to see what’s left of the original building and its views of the Plaza and Avenida de Mayo. 
5. Avenida de Mayo
The most historic thoroughfare in the city, this tree-lined avenue was modeled after Paris’s grand boulevards. It’s a showcase of handsome office buildings, hotels, cafes, and theaters—a smorgasbord of Spanish, French, English, and Italian Belle Epoque and Art Nouveau influence. A highlight is Casa de la Cultura, the 1889 headquarters of the newspaper La Prensa, with its Versailles-like interior. Running beneath the avenue is the historic A line of the subte, or subway, built in 1913—the first in South America. Estación Peru retains the most period charm, with turn-of-the-20th-century black-and-white photographs and charmingly old-school kiosks, tiles, and lamps transporting commuters back in time. Original wood-paneled cars, introduced in 1913 as part of the first subway system in South America, still run the line, even though newer cars have been introduced; if you’re riding as much for the experience as the transport, wait for one of the older cars. [
6. Café Tortoni
The oldest, as well as most famous and atmospheric, cafe in Buenos Aires, little has changed at this institution since 1858 except for the attire of its patrons. Although it looks like a museum piece, with its rich woods, huge mirrors, ornate light fixtures, and stained-glass ceilings, it remains an essential gathering place for locals, as well as hordes of visitors. Politicians, artists, and intellectuals through the years, including Carlos Gardel (1890–1935), Jorge Luis Borges (1899–1986), and Federico García Lorca (1898–1936), have all held court at Tortoni. In the back is a cool little theater hosting nightly tango music performances.
7. Palacio Barolo
One of the most distinctive buildings in the city, this 22-story “palace” was the tallest in the city when it was completed in 1923. The Italian architect Mario Palanti built it for a local textile magnate and curiously styled the building to closely reflect aspects of Dante’s The Divine Comedy. The lobby is gorgeous and the old-school elevators enchanting, but little prepares one for the breathtaking panoramic views from the top floors. 
8. Palacio del Congreso
At the end of Avenida de Mayo, forming a bookend with the Casa Rosada, is the imposing Greco-Roman Congress building, constructed in 1909 of gray granite and topped by a greenish copper dome. Tours of the Congress’s opulent interior take visitors to the Salón Rosado, now renamed for Eva Perón, who christened the room as a place where women, newly granted the right to vote, could discuss issues without the interference of men (Evita lay in state at Congreso for 2 weeks of public viewing after her death in 1952).
9. Avenida 9 de Julio/Obelisco
Whether or not it is in fact the widest street in the world, as Porteños claim, Agenda 9 de Julia is definitely a challenge to cross on foot. Developed in 1937, and widened in the 1960s to its current 16 lanes, the avenue is home not only to some of the city’s most important office buildings and a healthy share of its automobiles, but also to some lovingly landscaped garden areas. Four blocks to the north (at Corrientes), rising from the middle of the avenue, is the towering Obelisco, the symbol of Buenos Aires built in 1936 to commemorate the 400-year anniversary of the city’s initial founding. Major national sporting events are frequently celebrated here, though one year, to mark International AIDS Day, the monument was draped with a giant condom. 
10. Teatro Colón
Two blocks north of the obelisk, near Plaza Lavalle, is Buenos Aires’s renowned opera house, which received a stunning renovation for its 100th birthday in 2008. It’s one of the world’s great music palaces, essential to visit for a concert or, failing that, a tour.
11. Plaza San Martín
This lovely park in the Retiro district is one of Buenos Aires’s treasured green spaces, offering plenty of space to unwind in the heart of downtown. Palm trees, palos borrachos, and (in spring) the abundant lavender flowers of jacarandas frame views of an imposing skyscraper, the 1935 Edificio Kavanagh, and two stunning early-20th-century aristocratic mansions: the Palacio San Martín (former home to the Argentine Foreign Service), and Palacio Paz, a massive and extraordinary palace reminiscent of Versailles, with a miniature gilded opera house within and one wing housing the Círculo Militar, a weapons and military museum. 
12. Visit Cocktail Bar (Hotel Pulitzer)
Finish a long day of walking and sightseeing with a much-deserved drink at one of the city’s best hotel cocktail bars, a beautifully designed spot that serves terrific drinks, including a half-dozen takes on gin-and-tonics. If it’s early evening and the Sky Bar is open, head to the 13th floor for some of the finest views of the cityscape. 

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.