Those are over 100 pyramids, made of clay, have become nearly stone hard over the centuries. Many are damaged by erosion or farming. One pyramid is as large as the Pyramid of the Sun of Teotihuacan in Mexico (which is as large as the Great Pyramid of Giza). The big pyramid is about 1,000 feet high (other descriptions estimate 1,000 to 1,200 feet high) and roughly 1,500 feet at the base, which makes it twice as large as any pyramid in Egypt. Most are flat topped, some have small temples on top.