It also contains numerous museums, libraries, government offices, markets and other commercial centers which can bring in as many as 5 million people each day to work, shop or visit cultural sites.

Such efforts have resulted in better public parks, such as the Alameda Central, which was renovated; the modification of streets such as 16 de Septiembre and Madero that have become car-free for pedestrians (zona peatonal).

Cuauhtémoc is centered on the Zócalo or main square which contains the Aztec ruins of the Templo Mayor, the Metropolitan Cathedral and the National Palace of Mexico.

Currently, at least 789 inhabited buildings in twelve colonias have been listed as in danger of condemnation, due to structural damage caused by sinking into muddy soil of the former lakebed.

[11] This has been a problem for the area for centuries and has involved famous structures such as the Metropolitan Cathedral, which had major foundation work done to stop the damage caused by uneven sinking.

[13] Most of the 5 million who come into this borough each day are there to work, visit the area's markets, shops and cultural attractions or are tourists.

[13] People from other parts of the city come to visit the museums and large public markets such as La Lagunilla, Mixcalco, Hidalgo, Medellín and San Juan.

The influx brings in 800,000 vehicles to circulate its streets each day, with traffic jams, especially in and near the historic center nearly a daily occurrence.

A fairly large percentage of the population is either over 60 years of age and over half of the residents are either single or living with a partner.

[4] When the Spanish conquered Tenochtitlan in 1521, they destroyed most of the old Aztec public buildings but kept the basic layout of the city, which roughly extends over what is now known as the historic center or Colonia Centro.

Over the early colonial period, European-style construction would replace Aztec ones over the entire island city, with the most important public buildings concentrated on the blocks adjoining the Zocalo.

"[4] At the beginning of the 19th century, this city remained mostly within what is now called the historic center although various drainage projects had been enlarging the island.

The city proper contained 397 streets and alleys, 12 bridges, 78 plazas, 14 parish churches, 41 monasteries, 10 colleges, 7 hospitals, a poorhouse, a cigar factory, 19 restaurants, 2 inns, 28 corrals for horses and 2 official neighborhoods.

[4] By the late, 19th century, the city began to break its traditional confines with the construction of new neighborhoods, called colonias, in the still drying lakebed.

By the 1950s, the country's main university UNAM moved almost all of its facilities out of the borough and into the newly built Ciudad Universitaria in the south of the city.

[18] In the 1940s, the city government froze rents in the borough and by the late 1990s, when this was finally repealed, many tenants were paying the same prices they were in the 1950s.With no financial incentive to keep up their properties, landlords let their buildings disintegrate.

[21] Most of this occurred in the historic center, but this phenomenon also presented itself in other areas such as Colonia San Rafael[22] and the Centro Urbano Benito Juárez as well.

[27] Because of the rent situation, most of the damaged structures were never fixed or rebuilt, leading to slums or garbage-strewn vacant lots.

[30] Between the flight of wealthier residents from the historic center and the colonias that immediately surround it and the damage from the 1985 earthquake, parts of the borough became deserted at night.

[33] Starting in the late 1990s, the city and federal governments, along with some private associations have worked to revitalize the borough, especially the historic center.

[24] The borough government has been accused of corruption by the Cámara de Comercio, Servicios y Turismo (Chamber of Commerce, Services and Tourism), especially in the issuance of business permits with exorbitant fee and fines.

Public markets are buildings constructed and maintained by a city or municipal government, which rents stands to private vendors.

The vast majority of these are current and former residential streets, but there are also three expressways and various axis roads (ejes viales) for through traffic.

[53] The three main arteries are the Circuito Interior, Viaducto Miguel Alemán and San Antonio Abad, which were built for traffic passing through the center of the city.

[54] The ejes viales are a series of north-south and west-east roads built by Carlos Hank González in the 1980s to make Mexico City more automobile-friendly.

[13] The cycle rickshaw, known in Mexico as bicitaxi (from the English "bike taxi"), is a popular means of transport in the historic center.

[24] Private schools: Colegio Alemán Alexander von Humboldt previously had a campus at 43 Benjamin G. Hill in Hipódromo Condesa, in what is now a part of Universidad La Salle.