- Phase 3 - Edificios de los Tableros Lisos: The architectural technique of Phase 3, dated to the second half of the 2nd century AD, is similar to the previous ones, but a large plaza was added on its west side. In this phase the pyramid reached a height of about 20 m (66 ft) and measured 145 m (475 ft) north-south and 178 m (584 ft) east-west.
- Phase 4 - Edificio Escalonado I: During this phase, currently under study along with Phase 5, there was a change in construction technique and the primary building material shifted from adobe to stone. Furthermore the walls of this phase of the pyramid are not sloping, but rather stepped walls (escalonados).
- Phase 5 - Edificio Escalonado II: As the others, this construction covered all the previous ones and has the same characteristics as Phase 4. Archaeologists are currently studying this phase and registering it through 3D modeling and digital rendering.
- Phase 6: According to Marquina, this phase consisted in the construction of platforms adjoined to the main pyramid, and not in changes in the pyramid itself. A large platform, still in the traditional talud-tablero style, with a series of terraces and patios was constructed on the northeast corner of the main pyramid.
- Phase 7: This construction episode corresponds to the last enlargement of the great pyramid (around AD 750-950) before the religious focus was moved to the center of Cholula and the temple of Quetzalcóatl by the Tolteca-Chichimeca. The pyramid had high stepped walls and its base reached 300x400 m (~985-1310 ft) and rose 65 m (213 ft) high. On top of the main platform was another stepped pyramid on its rear side, with a large open space in front. Unfortunately, this construction, being the exposed one, was heavily damaged by the construction of the colonial church and, later, by the passage of a path on its north side.
- Phase 8: This last construction phase, which dated to the Postclassic, didn't involve main changes in the pyramid. However, several patios, platforms and rooms were added around the main structure. During the 1930s works, one of these platforms--dubbed "Altar of the skulls"--was excavated. The altar dates to the Postclassic and was decorated with sculptures of skulls on three sides. Inside the archaeologists found the burials of a man and a woman, each with offerings. This find proves that although the focus of religious life had already moved to another place, the pyramid maintained its sacred power and importance.


