The Cave of Hercules is a subterranean vaulted space dating back to Roman times located in the alley of San Ginés. The cave is under the Church of San Ginés.
The structure was likely constructed in the time of the Roman Empire, probably towards the second half of the 1st century, when it was used as a water reservoir. It is located in the east corner of the current courtyard and was built in two construction phases. It was covered with a barrel vault, realized in ashlar, and displayed the aspect of a great tank to the open sky, with an overflow at the edge. The first half of the wall, made in Roman concrete and covered with Opus signinum, is preserved, and overlooks San Ginés alley.
The structure was deeply altered with the construction of an arcade of three arches of ashlars in the southwest side. This divides the primitive one in two and currently separates it from the other half of the deposit, belonging to No. 2 of San Ginés street. It is unknown whether this change occurred in the first or second phase of construction. The second half of the northeast wall that faces the street was constructed in the second Roman phase. A facade was built in Opus quadratum of seven rows of ashlars of varying size, which is attached to the northeast lateral wall of the hydraulic structure of the first phase. The size was increased from the northwest to the southeast by creating a new line of orientation to the wall, which is the one that generates the trapezoidal plant that will have the nave. In this space, different rupture interfaces are observed along the entire surface.
In the Visigothic era, it is probable that there was a Visigothic church on the property. In the Al-Andalus period, constructions were developed, probably a mosque, in whose walls were embedded Visigothic reliefs. This mosque followed a structure similar to others of the city, being a small oratory with practically square plant, four interior columns and nine vaults or domes.
The first references to this property as the church of San Ginés come from 1148. At the end of this Late medieval epoch, or the beginning of the Early modern age, a series of changes were made, such as the creation of five individual chapels.
The building deteriorated during a prolonged period of the Early modern era. Abandoned and closed to the public during the 18th century, the church was demolished in 1841. The wall of the entrance, where several Visigothic reliefs are embedded, was partially preserved, as were the remains of the sacristy. The lot, including the vaults beneath, was put up for sale and was parceled out among several neighbors.
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.