This is the largest cathedral in Latin America, begun in 1567 and constructed over a period of 250 years. Built in a fanciful baroque style known as churrigueresque, it's filled with exquisite details and has many small, lavishly embellished chapels. It also boasts one of the largest organs in the world—concerts are given on special occasions. The cathedral is sinking into the swampy soil beneath it and it tilts to one side, which is clearly visible from the outside. Recent renovations have halted the sinking. Daily 8 am-8 pm. Free. On the north side of the Zocalo, Centro Historico, Mexico City.