Uxmal , Yucatan , Mexico : Quadrangle of the Nuns - western building with outstanding Puuc architecture frieze . This collection of four buildings around a quadrangle was named "Casa de las Monjas" (The Nunnery) by the Spanish, because the 74 small rooms around the courtyard reminded them of nuns?quarters in a Spanish convent. Each of the four buildings has a unique ornate fa蓷de, and each is built on a different level. The northern building is the oldest and the grandest; here you can see many typical Puuc embellishments - Chac masks arranged one over another vertically, serpents and lattice work. The building to the east and closest to the House of the Magician is the best preserved, with a stack of Chac masks over the central doorway and serpents above the doorways to the left and right. The exact purpose of the group is not known, though, given the size and importance of the site, it is thought likely to have housed visiting dignitaries or administrative offices.