In Hellenistic Greek and Roman architecture a peristyle (; from Greek περίστυλος) is a columned porch or open colonnade in a building surrounding a court which contains an internal garden. Tetrastoon (from Greek τετράστῳον, "four arcades") is another name for this feature. In the Christian ecclesiastical architecture that developed from Roman precedents, a basilica, such as Old St Peter's in Rome, would stand behind a peristyle forecourt that sheltered it from the street. In time the cloister developed from the peristyle.