The Arch of Trajan is an ancient Roman triumphal arch in Benevento, southern Italy. It was erected to celebrate Emperor Trajan across the Via Appia, at its entrance in the city. The arch was built between 114 and 117. The arch has a single, barrel-vaulted archway, and is 15.60 m-high and 8.60 m wide. Each facade has four semi-columns in correspondence of the two side pillars, supporting an entablature. Above the architraves is an attic which, like the latter, juts out above the archway.