This is one of the huge arches ever built in Rome. It reaches a height of 21 meters, almost 36 meters is its width, and the thickness of its walls exceeds 7 meters. The arch is built in 315 ad by decree of the Senate and the Roman people in honor of the tenth anniversary of Constantine's reign and victories in 312 at the battle of Ponte Milvio against Maxentius. To decorate this arch used a variety of bas-reliefs and sculptures taken from other monuments. On both of the big pillars of the arch are four columns Dating back to the era of the reign of Trajan; above the columns rise eight statues of Dacians in white with purple-veined marble of Asia Minor.

Over the side arches there are eight medallions of Hadrian era, grouped by two above each arch. Four depicted scenes in them reproduce scenes of hunting, four others - sacrifice. On either side of the inscription, repeated on two tapes Attica, you can see eight era bas-reliefs of Marcus Aurelius, adorned in his time, another triumphal arch and also placed two on each side. The bas-reliefs depict the solemn moment of the Return of the Emperor" in 173 year after victorious battles with the Germanic tribes of marcomanni and quads. Big marble frieze of the age of Trajan is also borrowing. It is divided into four parts: two pieces placed over the small arches, and two inside the Central passage. Sculptural reliefs reproduce scenes of military campaigns Trajan against the Dacians (101-102 and 105-106 years).