​COLONNADE, in architecture, a range of columns (Ital. colonna) in a row. When extended so as to enclose a temple, ​it is called a peristyle, and the same term applies when round an open court, as in the houses at Pompeii. When projecting in front of a building, it is called a portico, as in the Pantheon at Rome and the National Gallery in London. When enclosed between wings, as in Perrault’s façade to the Louvre, it is correctly described as a colonnade. Colonnades lined the streets of the towns in Syria and Asia Minor, and they were largely employed in Rome.