THE MIDDLE CIVILIZATIONS 159 



platform mound. The sides of the platform mound 

 are decorated with great plumed serpents, seated human 

 figures, hieroglyphs, etc. Parts of the sculptures also 

 remain on the low walls of the temples itself which is 

 now roofless. The stone carving at Xochicalco re- 

 sembles that of Monte Alban especially as regards the 

 hieroglyphs. 



San Juan Teotihuacan. The great ruin of 

 Teotihuacan is located on the eastern margin of the 

 Valley of Mexico. The principal features of Teotihua- 

 can are two great pyramids and a straight roadway lined 

 with small pyramids. There are also several groups 

 of buildings of which the lower walls and the bases of the 

 piers are still to be seen as well as some interesting 

 fragments of fresco painting. The smaller of the two 

 great pyramids is called the Pyramid of the Moon. 

 It is located at the end of the roadway which is com- 

 monly called the Pathway of the Dead. The Pyramid 

 of the Sun is situated on the east side of the roadway. 

 This pyramid is about 180 feet in height and rises in 

 four sloping terraces. The temple which formerly 

 crowned its summit has entirely disappeared. Explo- 

 rations conducted by the Mexican government showed 

 that this pyramid was enlarged from time to time and 

 old stairways buried under new masonry. On the 

 south side of the small stream that flows through the 

 ruins is a group of buildings called the Citadel. 



In 1921 the Mexican Government provided funds for 

 a restoration of the Citadel under the direction of 

 Doctor Manuel Gamio, following the discovery by him 

 of remarkable sculptures on the principal pyramid. It 

 appears that in ancient times this pyramid was enlarged 

 by an addition to one side and the richly ornamented 

 terraces and stairway buried (Plate XXXII). The 



