propylaeum

In ancient Greek architecture, a structure forming an entrance or gateway to a sacred enclosure, usually consisting, at the least, of a porch supported by columns both outside and within the actual gate. The term is often used in the plural (propylaea). The most famous example is the great Propylaea designed by Mnesicles for the Athenian Acropolis. The name propylaea was also applied to various 18th19th-century Neoclassical and Romantic monumental gateways.

propylaeum (prŏpĭlē'əm), in Greek architecture, a monumental entrance to a sacred enclosure, group of buildings, or citadel. A roofed passage terminated by a row of columns at each end formed the usual type. Known examples include those at Athens, Olympia, Eleusis, and Priene. The most splendid example are the Propylaea at Athens upon the west end of the Acropolis; their restored remains still stand. Of Pentelic marble, they were built (437-432 B.C.) at the command of Pericles by the architect Mnesicles.