The vast paved open space of the Zócalo – properly known as the Plaza de la Constitución – was once the heart of Aztec Tenochtitlán, and is today one of the largest city squares in the world after Beijing’s Tiananmen Square and Moscow’s Red Square. The city’s political and religious centre, it takes its name from part of a monument to Independence that was planned in the 1840s for the square by General Santa Anna. Like most of his other plans, this went astray, and only the statue’s base (now gone) was ever erected: el zócalo literally means “the plinth”. By extension, every other town square in Mexico has adopted the same name. It’s constantly animated, with pre-Hispanic revivalist groups dancing and pounding drums throughout the day and street stalls and buskers in the evening. Stages are set up here for major national holidays and, of course, this is the place to hold demonstrations. Over one hundred thousand people massed here in March 2001 to support the Zapatistas after their march from Chiapas in support of indigenous people’s rights; in July 2006 the square proved too small to contain the millions of demonstrators who gathered to challenge the result of that year’s presidential election, a contest widely believed – especially in the left-leaning DF – to have been fixed. Spreading out from the Zócalo, the crowds reached as far as Paseo de la Reforma.

Though you’re not guaranteed to see any protests, among the Zócalo’s more certain entertainments is the ceremonial lowering of the national flag from its giant pole in the centre of the plaza each evening at sundown (typically 6pm). A troop of presidential guards march out from the palace, strike the enormous flag and perform a complex routine at the end of which the flag is left, neatly folded, in the hands of one of their number. With far less pomp, the flag is quietly raised again around half an hour later. You get a great view of this, and of everything else happening in the Zócalo, from the rooftop terrace restaurants in the Hotel Majestic and Gran Hotel Ciudad de México on the west side of the square.

The Zócalo does, of course, have its less glorious aspects. Mexico City’s unemployment rate is tellingly reflected by the people who line up on the west side of the cathedral seeking work, each holding a little sign indicating their trade.