A triumphal arch is a structure in the shape of a monumental archway, in theory built to celebrate a victory in war, actually used to celebrate a ruler. The classical triumphal arch is a free-standing structure, quite separate from city gates or walls, but the form is often used in engaged arches as well. In its simplest form a triumphal arch consists of two massive piers connected by an arch, crowned with a flat superstructure or attic on which a statue might be mounted or which bears commemorative inscriptions.
The structure should be decorated with carvings, notably including "Victories", winged female figures (very similar to angels), a pair of which typically occupy the curved triangles beside the top of the arch curve. More elaborate triumphal arches have flanking subsidiary archways, typically a pair.
The rhythmic ABA motif—of central arched void flanked by smaller ones—was adapted in Classical architecture, particularly since the Renaissance, to articulate the walls of structures. The voids may take the form of niches or be "blind", with masonry continuous behind.