Monocle Travel Guide, Mexico CityQuesadillas sizzling on street corners outside cosy coffee shops; mariachi in sequined sombreros serenading late night revellers; tower blocks casting long shadows over baroque churches and Aztec ruins studded with cacti. Mexico City simultaneously conforms to every stereotype and challenges every preconception with shameless self assurance. We push past the colourful chaos and Frida Kahlo merchandise (although, naturally, we drop by her cobalt blue