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Unknown Era · Gate41.8893°N, 12.4828°E

Ianus Quadrifons

At the edge of the Forum Boarium, where Rome’s oldest cattle market met the Velabrum, stands a curious arch with four faces. The Ianus Quadrifrons is a quadrifrons triumphal gate, built in the early fourth century AD at a busy crossroads. Unlike the more familiar single-passage arches, this one is a square block, pierced by four equal vaulted openings, so that all directions of traffic passed through it.

Its construction was pragmatic, even scavenged: much of the stonework is spolia, recycled from older buildings. The arch likely honoured either Constantine I or Constantius II, though no inscription survives to confirm which. What remains is a solid, somewhat squat monument, its marble cladding long stripped away, revealing a core of brick and concrete. Standing there, you sense a city in transition, still imperial, but already turning to the past for materials and meaning.

Description via source. Coordinates and heritage data from the Atika atlas.

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