The relatively short period of occupation at Mixco Viejo (Jilotepeque Viejo) led to an unusual unity of architectural styles for a Mesoamerican city. Almost all archaeological finds at the city, including both artefacts and earlier versions of later structures, date to the last few hundred years before the Spanish conquest. The architecture was built with mica and pumice slabs, in some cases this was coated with stucco. Stone sculpture is almost totally absent from the city, the only example being a ballcourt marker in the form of a serpent's head with jaws agape and a human head emerging from its mouth. Originally some buildings were decorated with painted stucco but this is so poorly preserved that only a few fragments remain.