Mexico City’s Catedral Metropolitana stomps on the Aztec grave like an inelegant elephant. The monstrous grey church was built by Spanish conquistadors in 1573 on the ruins of the Templo Mayor in what was called Tenochtitlan by the old rulers of the great city, to serve a similar purpose to the giant stone slabs laid on top of graves in ancient times: to keep the dead dead.

The dead are resting uneasy, though, and the cathedral is slowly, and unevenly, sinking. Walking around it, you can seek cracks in the stone where the floor has decided to go in different directions. How long the church will stand is anyone’s guess.

Just to the east, the bones of the old temple stick out of the ground. The temple that stood here astounded the Spanish when they first arrived. First built in the 1300s, it was enlarged seven times and grew to a glorious 40-metre high pyramid with two temples on the top. While the Aztecs no doubt celebrated each growth as a sign of their empire’s growing power, it was bad news for others – some 20,000 people were sacrificed to consecrate an addition in the 1400s.

Inside is a decent museum gives you an overview of the Aztec empire – think of them as the New World’s Romans, compared to the earlier Maya’s Greece.

Despite what Torontonians may think, Mexico City is in fact the centre of the universe. The Aztecs were wandering around the swampy basin back in the day, thinking it was time to settle down, when they saw an eagle sitting on a cactus, chewing on a snake. Obviously, this meant it was the centre of everything, and the place for them to build a city. Take a good look at the Mexican flag next time you see it.

Mexico City is huge – 18 million people call it home, with thousands more arriving by the day – but on an old scale. The streets are narrow, clogged with people, vendors and cars, and most of the buildings maintain a European colonial feel. While it is unlikely that Mexicans will ever be confused with Parisians when it comes to style, they make up for it in the splendid array of uniforms. Traffic cops, riot cops, pick-up truck riding cops, cops on bikes, soldiers on patrol: everyone’s got a sash in Mexico City.

Hop in the elevator at the Torre Latinoamericana and ask the operator to take you to the 44th floor for a stunning, panoramic view of Mexican smog. The mountains that you can’t see in the distance will take your breath away. Or maybe that was just the pollution.