"The region behind or south of the two converging ranges of low hills that come together just northwest of Uxmal is called the Puuc (Maya hilly country). During the eleventh and twelfth centuries, this section of Yucatan supported the densest population in the entire northern half of the Peninsula, a population which was gathered around many ceremonial centers, the most important of which was Uxmal...and the second largest, Kabah, located only nine miles southeast of Uxmal and connected therewith by a stone causeway. Kabah was doubtless a dependent city of the Xiu state, since it was so near the Xiu capital and, moreover, is connected with it by the causeway just mentioned.
The most interesting structure at Kabah is the so-called Palace of the Masks [Codz Poop], which is 151 feet long and contains ten handsome chambers arranged in two tiers of five each; the chambers of each pair are built one directly behind the other, with a single outside doorway for each pair. The exteriors of most Maya buildings...are usually devoid of sculptural decoration below the medial molding, while the often exceedingly rich and intricate mosaics are principally concentrated in the upper half of the façades. The Palace of the Masks, however, is different in this respect. It stands on a low platform, the face of which is decorated with a single row of mask panels; above this is a rich lower molding, surmounted by the lower half of the façade composed of three rows of mask panels running entirely across the front of the building. The medial molding of this building is perhaps the most ornate of any in Yucatan; above it, in the upper half of the façade, there are again three rows of mask panels, the top-most row being surmounted by a third and terminal molding. The effect of this lavishly sculptured façade is overwhelming, and the building itself is one of the handsomest examples of Puuc architecture that has come down to us.
Another unique feature at Kabah is the stone arch. It stands disconnected from any other building at the beginning of the stone causeway leading to Uxmal, the arch having a span of fifteen feet. What was it? --a triumphal arch commemorating some long-forgotten Maya victory? Or, perhaps more likely, was it a formal gateway dedicated to some deity of the Maya pantheon? Who knows? All who could have told are gone, and these questions, like so many others, remain unanswered."
Sylvanus G. Morley, The Ancient Maya, p.341-2