Colonnade
In classical architecture, a colonnade is a long sequence of columns joined by their entablature, often free-standing, or part of a building. Paired or multiple pairs of columns are normally employed in a colonnade which can be straight or curved. The space enclosed may be covered or open. In St. Peter's Square in Rome, Bernini's great colonnade encloses a vast open elliptical space.
When in front of a building, screening the door, it is called a portico. When enclosing an open court, a peristyle. A portico may be more than one rank of columns deep, as at the Pantheon in Rome or the stoae of Ancient Greece.
When the intercolumniation is alternately wide and narrow, a colonnade may be termed "araeosystyle", as in the case of the western porch of St Paul's Cathedral and the east front of the Louvre.