Platform C2 faces Pyramid C1 and borders the Group C Plaza. The platform is a long rectangular structure measuring (north-south by east-west) and occupies the highest location of any structure at Mixco Viejo (Jilotepeque Viejo). The platform has two levels and has a total height of , the lower of which has a prominent cornice. The east side of the lower level has an inset stairway accessing the upper level. The upper level of the platform is recessed against the rear of the lower level and possesses an elaborate facade with four access stairways separated by corniced ramps. The entire platform was originally coated in stucco, of which only a few traces remain. On the upper level the stucco traces outline where walls once stood, leading archaeologists to conclude that several residential structures once stood on top. Platform C2 was built upon an earlier, shorter platform that possessed a facade composed of thin slabs. It is likely that Platform C2 provided restricted access to Pyramid C1. A number of funerary urns were excavated from the base of Platform C2.