Campeche

A UNESCO World Heritage fortified colonial port city on the Gulf of Campeche whose hexagonal Spanish military walls — the finest surviving colonial fortification system in Mexico — enclose a grid of candy-colored houses. The baluarte system of seven bastions connected by city walls, now converted into museums and gardens, offers the most comprehensive preserved colonial military architecture in the Americas, with walls stretching 2.5 kilometers — 30% longer than the runner-up in Cartagena.