In Hellenistic Greek and Roman architecture, a peristyle (/ˈpɛrɪstaɪl/; from Greek περίστυλον) is a continuous porch formed by a row of columns surrounding the perimeter of building or a courtyard. Tetrastoön (τετράστῳον or τετράστοον, 'four arcades') is a rarely used archaic term for this feature. The peristyle in a Greek temple is a peristasis (περίστασις). In the Christian ecclesiastical architecture that developed from the Roman basilica, a courtyard peristyle and its garden came to be known as a cloister.