Located to the south of Complex A, it consists of a platform on which the main pyramidal foundation (building C-1) was built. It is 30 m high and offers an unobstructed 360-degree view. Its last construction stage dates from approximately 400 B.C.; it is considered the oldest for its type and size. The complex was built with rammed earth (clay and sand), held in place by limestone slabs, as a kind of internal buttresses. On its south side six tombstones carved in bas-reliefs were found, arranged symmetrically on the sides of a central staircase. In front, a pair of altars were located, stone sculptures with a central niche from which an individual emerges in a seated position.

Visitors can see the replicas of these works in their original architectural context and get a glimpse of the harmonious proportion between architecture and sculpture.

Building C-1: This structure, mounted on a platform on which the main pyramidal base was built, measures more than 30 m and is the tallest in the archaeological zone. Six sculptures were found symmetrically arranged on the sides of a possible central stairway.