The Arch of Augustus was erected in 25 BC on the occasion of the Roman victory over the Salassi and was the work of Aulus Terentius Varro Murena.
Constructed from conglomerate, the arch has a single vault, with a height to the keystone of 11.4 metres. Its span is a barrel vault, constituting an extension in width of a round arch. In the monument, various styles can be recognised: The ten engaged columns which decorate its facade and its sides culminate in Corinthian capitals, while the entablature, adorned with metopes and triglyphs, is of the Doric order.
During the twelfth century, the arch contained the home of a local noble family and in 1318 a small fortification was built inside it, designed for a corps of crossbowmen. In 1716, because of the numerous leaks that were compromising the integrity of the monument, the attic that previously crowned the arch was replaced with a slate roof.
The arch's modern appearance is the result of a final intervention for restoration and consolidation which occurred in 1912 under the direction of Ernesto Schiaparelli.
The wooden crucifix displayed below the vault is a copy of the one which was placed there in 1449 as a votive offering against the flooding of the river Buthier, which flows a little to the east. The original crucifix is now housed in the Museum of Aosta Cathedral's Treasures.References:
Derbent is the southernmost city in Russia, occupying the narrow gateway between the Caspian Sea and the Caucasus Mountains connecting the Eurasian steppes to the north and the Iranian Plateau to the south. Derbent claims to be the oldest city in Russia with historical documentation dating to the 8th century BCE. Due to its strategic location, over the course of history, the city changed ownership many times, particularly among the Persian, Arab, Mongol, Timurid, Shirvan and Iranian kingdoms.
Derbent has archaeological structures over 5,000 years old. As a result of this geographic peculiarity, the city developed between two walls, stretching from the mountains to the sea. These fortifications were continuously employed for a millennium and a half, longer than any other extant fortress in the world.
A traditionally and historically Iranian city, the first intensive settlement in the Derbent area dates from the 8th century BC. The site was intermittently controlled by the Persian monarchs, starting from the 6th century BC. Until the 4th century AD, it was part of Caucasian Albania which was a satrap of the Achaemenid Persian Empire. In the 5th century Derbent functioned as a border fortress and the seat of Sassanid Persians. Because of its strategic position on the northern branch of the Silk Route, the fortress was contested by the Khazars in the course of the Khazar-Arab Wars. In 654, Derbent was captured by the Arabs.
The Sassanid fortress does not exist any more, as the famous Derbent fortress as it stands today was built from the 12th century onward. Derbent became a strong military outpost and harbour of the Sassanid empire. During the 5th and 6th centuries, Derbent also became an important center for spreading the Christian faith in the Caucasus.
The site continued to be of great strategic importance until the 19th century. Today the fortifications consist of two parallel defence walls and Naryn-Kala Citadel. The walls are 3.6km long, stretching from the sea up to the mountains. They were built from stone and had 73 defence towers. 9 out of the 14 original gates remain.
In Naryn-Kala Citadel most of the old buildings, including a palace and a church, are now in ruins. It also holds baths and one of the oldest mosques in the former USSR.
In 2003, UNESCO included the old part of Derbent with traditional buildings in the World Heritage List.