structure 5d-90, the westernmost, is rectangular with two small stepped platforms supporting the superstructure. it has 5 doorways in both its north and south facades. the north side of the building was accessed via a central stairway. the superstructure had terraces fronting its north and south sides, although the northern terrace was narrower than that on the south side. the facades of the structure are believed to have been decorated with friezes. the upper sections of the building have suffered extensive damage and fallen stones have been found decorated with wave-like sculpture, indicating that the building once supported either friezes or a decorated roof comb, although no trace of the latter now stands. structure 5d-90 was built during the late classic and was reworked in the terminal classic. the building originally had two rooms, accessed respectively via the doors in the north and south facades and joined by a wide central doorway in the dividing wall. due to its particular characteristics, in the late classic this building is believed to have served a civic administrative function rather than being used for domestic activity. in the terminal classic, the two rooms were subdivided to form five rooms with the construction of thin internal walls measuring approximately thick. one wall divided the former north chamber into two rooms, and two further walls divided the south chamber. three of the rooms may have been used for residential purposes and the remaining two continued to serve an administrative function. at the same time a low platform was built upon the southern terrace, which may have supported a perishable structure. a large amount of archaeological remains were found scattered around the building upon its final floor level, including almost 23,000 ceramic fragments as well as pieces of bone, shell, greenstone, obsidian and flint.