The greatest contribution of Mayan art lies in architecture. In addition to the value of the building itself, it also shows other artistic achievements, such as sculpture, painting and mosaic technology. Mayan public buildings are arranged around courtyards or squares, becoming places for religious and political activities. Mayan architecture includes temples, palaces, pyramids, stadiums and observation decks. These buildings often form groups, and some have vaults supported by beams. This vault is based on a thatched roof. Maya's vault is very thick, and it needs thick walls to support it. There are no windows, so the interior of the building is generally dark and narrow, and the main decorations are outside.