[5] This is where the Spaniards began to build what is now modern Mexico City in the 16th century on the ruins of the conquered Tenochtitlan, capital of the Aztec Empire.

[3] As the centre of the ancient Aztec Empire and the seat of power for the Spanish colony of New Spain, the Centro Historico contains most of the city's historic sites from both eras as well as a large number of museums.

During the prehispanic era, the city developed in a planned fashion, with streets and canals aligned with the cardinal directions, leading to orderly square blocks.

[6] After the Spanish conquest, this design remained largely intact, mostly due to the efforts of Alonso Garcia Bravo, who supervised much of the rebuilding of the city.

The Palacio Nacional borders the entire east side of the Zocalo and contains the offices of the President of Mexico, the Federal Treasury, the National Archives as well as murals depicting pre-Hispanic life and a large mural filling the central stairway depicting the entire history of the Mexican nation from the Conquest on.

Facing the Zócalo above a central balcony is the Campana (Bell) of Dolores, which is rung by the president each 15th of Sept to celebrate Independence.

The site originally was part of the Aztec Sacred Precinct (called the Teocalli) and contained the main tzompantli, or rack for the skulls of sacrifice victims.

[15] Between 1989 and 2000 extensive engineering works were conducted to arrest and rectify damage and distortions caused to the structure by the uneven rate and extent of the sinking of the building provoked by the continuous settlement of the ground on which it stands.

The exact site was determined in the beginning of the 20th century, but the decision to excavate was not made until 1978, when electrical workers chanced upon an eight-ton stone disk depicting the Aztec goddess Coyolxauhqui.

This is the spot where, according to legend, the Aztecs saw their sign to settle from their wanderings, an eagle perched on a nopal cactus with a snake in its beak, which is still the symbol of Mexico today.

[2] Officially known as the Señor de la Expiación Chapel, the church is located on the north side of Belisario Dominguez and faces the plaza.

A statue of Josefa Ortiz de Domínguez, a heroine of the Mexican War of Independence stands in a fountain in the middle of the plaza.

[17] The San Ildefonso College currently is a museum and cultural center considered to be the birthplace of the Mexican muralism movement.

The museum has permanent and temporary art and archeological exhibitions in addition to the many murals painted on its walls by José Clemente Orozco, Diego Rivera and others.

[23] The interior of the building contains four panels painted in 1941 by José Clemente Orozco, two of which are named "The Social Labor Movement" and "National Wealth."

[23] The Palace of Iturbide - this large palatial home on Madero Street #17 was built by the Count of San Mateo Valparaíso in the 18th century as a wedding gift for his daughter.

It is recognizable by Manuel Tolsá's large equestrian statue of Charles IV of Spain who was the monarch just before Mexico gained its Independence.

It is housed in what was the Palacio del Arzobispado (Palace of the Archbishopric), built in 1530 under Friar Juan de Zumárraga on the base of the destroyed pyramid dedicated to the Aztec god Tezcatlipoca.

[31] The José Luis Cuevas Museum is located just off the city's main plaza, or Zócalo, in a building that was the convent for the neighboring Church of Santa Ines (Agnes of Rome).

[33] The house was originally constructed by Gerónimo de Aguilar in 1524 and is located on the outer edge of what was the sacred precinct of the Templo Mayor prior to the Conquest.

[2] Mexico City's Chinatown, known locally as "Barrio Chino", is located on two blocks of Dolores Street, just south of the Palacio de Bellas Artes.

Its diminished size is because most descendants of Chinese immigrants to Mexico in the late 19th and early 20th centuries either intermarried with the local Mexican population and/or were expelled from the country in the 1930s.

The Centro remained the commercial, political and intellectual center through the mid 20th century although it was around this time that UNAM moved most of its facilities to the new Ciudad Universitaria.

[36] By the 1980s, so many had fled the Centro that many of its former mansions were either abandoned or turned into tenements for the poor,[2][37] and its sidewalks and streets taken over by pickpockets and milling vendors.

By law, religious institutions cannot appeal to the government for financial help, but agencies like the National Council for Culture and Arts (CONACULTA) do have say in how these places are maintained because of their historic value.

However the Archdiocese of Mexico believes that the structural problems noted constitute a grave danger to both people and to the "incalculable artistic and historic value of the buildings.

The San Lorenzo and Loreto churches both have had incidences where large pieces of the building, a stone and a window respectively, have fallen, causing damage but no injuries.

Another problem is that the depopulation of the historic center, which leaves these churches fairly empty and the diocese unable to fund restoration work.

[40] Work began with the beautification of 34 blocks just north of the Zócalo, digging up the antiquated drainage system and improving water supply.

According to the Historic Center of Mexico City Trust, this has led to the creation of 15,000 jobs and property owners in the area are showing interest in improving on their investments here.