Uxmal, particularly beautiful at sunset, is one of the best preserved Mayan cities and was the centre of the cultural area known as Puuc (the name comes from a range of hills stretching over the northwestern Yucatán) that flourished between the 7C and 10C AD. Low elongated structures with fine proportions characterise the style known as Puuc, as well as a specific décor: stones carved and laid out in geometrical mosaics and recurring masks of Chaac, the god of rain, a sign indicating an arid region.