Mexico City is the world's third-largest metropolis (only Tokyo and NYC are bigger). Mexico's best and worst ingredients are all here: music and noise, brown air and green parks, colonial palaces and skyscrapers, world-renowned museums and ever-spreading slums. One moment the city is all Latin beats, glamour and excitement; the next it's drabness, poverty, suffocating crowds and rancid smells. In spite of the negatives, Mexico City is a magnet for Mexicans and visitors alike. You certainly won't be bored.