Uxmal

The site is considered the finest and most extensively excavated example of Puuc architecture, which embraces such details as ornate stone mosaics and friezes on the upper walls, intricate cornices, rows of columns, and soaring vaulted arches.

You could easily spend a couple of days exploring the ruins, though keep in mind that the only entertainment offered outside the ruins is provided by hotels and the odd restaurant. Unlike some of the other remote ruin sites, here you can buy food, drinks, and souvenirs at the entrance.