If Chichén Itzá is the most expansive Mayan ruin in Yucatán, Uxmal is arguably the most elegant. The architecture here reflects the late classical renaissance of the 7th to 9th centuries, and is contemporary with that of Palenque and Tikal, among other great Mayan cities of the southern highlands. Uxmal 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—just keep in mind that the only entertainment offered outside them is provided by hotels and the odd restaurant. The upside is that, unlike some other remote ruin sites, you can buy food, drinks, and souvenirs at the entrance.