We have a few different walking tours of Buenos Aires here on About.com Argentina.  Among them, you’ll find Calle Florida which is important for shopping.  Another includes Avenida de Mayo, which was built at the turn of the last century, when Buenos Aires was coming into its own.  There is also Plaza San Martin and its surroundings.

What I call this tour is  "classical Buenos Aires" - the structures created largely around the turn of the last century, when the city rebuilt itself in the image of Paris.

It does take in Avenida de Mayo, and it is really one of the tours I give when friends visit me in Buenos Aires.  It allows me to take in components of the most important walking tours, and gives me a few hours to spend with friends and highlight certain don’t miss structures.

The majority of these buildings were built in time for the 1910 Centennial, when Buenos Aires wanted to show itself off to the world as an important city.  Money was flush and the structures were grand, and these are the buildings that were, or were intended to be, renovated or undergoing renovation in anticipation of the Bicentennial in 2010.  This being Argentina, not everything was done as it should have been.

I usually begin in the Plaza de Mayo, where the Casa Rosada, famous for Evita's balcony, had been restored. Visitors can tour the inside and also the Presidential Museum. Nearby on the Plaza are the Catedral Metropolitana which holds the tomb of General San Martin who liberated Argentina from Spain.  It is also famous as the former home of Archbishop Bergoglio, now Pope Francis.

  You will also see here the Cabildo, the old city hall, where Independence was declared. The Cabildo also hosts a crafts fair on select days, and vendors in the Plaza de Mayo sell food for the pigeons, a delight for families with children.

Heading up from the Plaza is the Avenida de Mayo, designed as a procession route lined with Art Nouveau and Beaux Artes structures to connect the Casa Rosada with the Congreso. A facade program enacted by the city's cultural office has meant that many of the once crumbling facades have been restored, though not nearly enough. The cultural office itself is housed in one of the Avenida's most sumptuous structures, a granite and bronze confection topped by the Lady of Freedom of Speech, marking its former use as the headquarters of the La Prensa newspaper. Open to the public, the interior is a riot of carved wood, etched glass and gilded columns, especially in the Salon Dorado, designed to mimic Versailles, and where cultural events are staged.

Up ahead on the street is the Palacio Vera, one of the best examples of art nouveau on the Avenida. Nearby is the uber-famous Cafe Tortoni, a must stop for all Buenos Aires tourists to grab a coffee and amidst its honey-marble, wood and bronze interior. At night, they hold tango shows in their small, intimate theatre.

There are several other buildings to take a look at through the Avenida, and one of the most mystical and dramatic is the Palacio Barolo, opened in 1928 as the tallest building in South America. Designed by the eccentric Italian architect Mario Palanti, a fascist Mussolini lover and Dante freak, the building tells the story of the Divine Comedy, with a lobby representing Hell, complete with ornate dragon studded columns, and a rooftop lighthouse representing Heaven and Salvation. The office workers are in Purgatory, naturally. Tours take you through the building and explain the Masonic symbols throughout, and there are winetastings in the 1920's office of the building manager.

Just around the corner from Palacio Barolo is the Castelar Hotel, one of the city's most storied, and also designed by Palanti. Its main attraction is the room that Spanish playwright Federico Garcia Lorca stayed in for 6 months when he worked in Buenos Aires and showed his plays at the nearby Teatro Atlantica. The room is preserved as a mini-museum to his work.

There are almost too many choices of buildings to mention along Avenida de Mayo, but other highlights include the Hotel Majestic. It was opened in 1910 and was where the Infanta Isabel stayed to represent Spain during the Centennial celebrations, as well as where ballet legend Nijinski stayed for his wedding night after marrying in Buenos Aires in 1913. Nearby is the Chile Hotel, a mix of art nouveau and Moroccan architecture which I personally find exquisite.

The Avenida ends at Congreso, the city's most imposing building, also renovated for the 2010 Bicentennial and open for tours. It was first opened in 1906,and if you look closely at the façade, you will see it takes design elements from the Brandenburg Gate, St. Peter's in Rome, the U.S. Congress and Garnier's Opera House in Paris. Virtually the entire interior's marble, bronze, glass and wood ornamentation was imported from Europe.

These are my personal don’t miss sites when I am showing Buenos Aires to friends.