Centre. Metro Hidalgo
Strictly speaking this is neither quiet nor calm. But it could be, with a pair of headphones and bit of imagination. Cars, trucks, motorbikes are not far off, all honking their horns obviously, and the general hubbub of the city still swirls around you here.
But you don't care because you have the entire road, all 6 lanes of it, to yourself. By 'yourself' I mean you and your new family of roller skaters, cyclists and joggers, for whom the Paseo is closed off every Sunday from 7am to 2pm. There's a large-ish and helpful police presence, there's free water, medical assistance and even the bike hire is free. What's not to like?
This isn't a particularly new idea, to be fair. Paris has something similar, as does Bogotá, Quito, and, I'm lead to believe, Carshalton. But there's something quite satisfying in keeping at bay the traffic in one of the worst polluted, most vehicle-blighted cities in the world. Now if they could just stretch it out to every day, and the entire city....