The main ceremonial space within the ounfò is the "peristil" or "peristyle". In the peristil, brightly painted posts hold up the roof, which is often made of corrugated iron but sometimes thatched. The central one of these posts is the "poto mitan" or "poteau mitan", which is used as a pivot during ritual dances and serves as the "passage of the spirits" by which the lwa enter the room during ceremonies. It is around this central post that offerings, including both vèvè and animal sacrifices, are made. However, in the Haitian diaspora many Vodouists perform their rites in basements, where no poto mitan are available. The peristil typically has an earthen floor, allowing libations to the lwa to drain directly into the soil, although outside Haiti this is often not possible, with libations instead poured into an enamel basin. Some "peristil" include seating around the walls.