Villahermosa, Mexico

This sprawling, flat, hot and humid city, with over a quarter of Tabasco's population, was never the 'beautiful town' its name implies, but it takes advantage of its position on the winding Río Grijalva, with a welcome riverside leisure development a couple of blocks from the pedestrianized city center. Still, when the river burst its banks and engulfed the city in 2007, the result looked like New Orleans after Hurricane Katrina.