The Temple of Garni  is the only standing Greco-Roman colonnaded building in Armenia. A Ionic temple located in the village of Garni, Armenia, it is the best-known structure and symbol of pre-Christian Armenia.

The structure was probably built by king Tiridates I in the first century AD as a temple to the sun god Mihr. After Armenia’s conversion to Christianity in the early fourth century, it was converted into a royal summer house of Khosrovidukht, the sister of Tiridates III. According to some scholars it was not a temple but a tomb and thus survived the universal destruction of pagan structures. It collapsed in a 1679 earthquake. Renewed interest in the 19th century led to excavations at the site in early and mid-20th century and its eventual reconstruction between 1969 and 1975. It is one of the main tourist attractions in Armenia and the central shrine of Armenian neopaganism.

The temple is at the edge of a triangular cliff which overlooks the ravine of the Azat River and the Gegham mountains. It is part of the fortress of Garni.One of the oldest fortresses in Armenia, it is mentioned as Gorneas in the first-century Annals of Tacitus. The fortress was strategically significant for the defense of the major cities in the Ararat plain. The site is in the village of Garni, in Armenia’s Kotayk Province and includes the temple, a Roman bath with a partly preserved mosaic floor with a Greek inscription, a royal summer palace, the seventh century church of St. Sion and other minor items.

The precise construction date of the temple is unknown and is subject to debate. The dominant view is that it was built in 77 AD, during the reign of king Tiridates I of Armenia. The date is calculated based on a Greek inscription, discovered by artist Martiros Saryan in 1945 in the fortress wall, which names Tiridates the Sun (Helios) as the founder of the temple. 

Most scholars now attribute the inscription to Tiridates I. Considering that the inscription says the temple was built in the eleventh year of reign of Tiridates I, the temple is believed to have been completed in 77 AD. The date is primarily linked to Tiridates I’s visit to Rome in 66 AD, where he was crowned by Roman emperor Nero. To rebuild the city of Artaxata, destroyed by the Roman general Gnaeus Domitius Corbulo, Nero gave Tiridates 50 million drachmas and provided him with Roman craftsmen. Upon his return to Armenia Tiridates began a major project of reconstruction, which included rebuilding the fortified city of Garni. It is during this period that the temple is thought to have been built.

The temple is believed to have been dedicated to Mihr, the sun god in the Zoroastrian-influenced Armenian mythology and the equivalent of Mithra. Tiridates, like other Armenian monarchs, considered Mihr their patron. Some scholars have argued that the historical context during which the temple was built, i.e. after returning from Rome as king, it is natural that Tiridates dedicated the temple to his patron god. Furthermore, white marble sculptures of bull hooves have been discovered some 20 metres (66 ft) from the temple which could possibly be the remains of a sculpture of the god Mihr, who was often portrayed in a fight with a bull.

In the early fourth century, when Armenian King Tiridates III adopted Christianity as a state religion, virtually all known pagan places of worship were destroyed.^[32] The Temple of Garni is the only pagan, Hellenistic,and Greco-Roman structure to have survived the widespread destruction. It remains unknown why the temple was exempted from destruction, but philosopher Grigor Tananyan argues that its status as a „masterpiece of art” possibly saved it from destruction. He suggests that the temple was perceived to be a „quintessence of an entire culture.” Robert H. Hewsen suggested that the reason why it was not destroyed is because it was not a temple, but a tomb of a Roman-appointed king of Armenia. He also noted that in the seventh century a church was built immediately next to it and not in its place.

According to Movses Khorenatsi a „cooling-off house” (summer house) was built within the fortress of Garni for Khosrovidukht, the sister of Tiridates III. As its purpose changed the temple underwent some changes. The sacrificial altars in the outside of the temple and the cult statue in the cella were removed. The opening in the roof for skylight was closed. The stone structures for removal of water from the roof were also removed, while the entrance of the temple was transformed and adjusted for residence. There is a series of Arabic graffiti on the walls of the temple, dated 9th-10th centuries.

In 1949 the Armenian Academy of Sciences began major excavations of the Garni fortress site led by Babken Arakelyan. Architectural historian Alexander Sahinian focused on the temple itself. It was not until almost twenty years later, on December 10, 1968, that the Soviet Armenian government approved the reconstruction plan of the temple. A group led by Sahinian began reconstruction works in January 1969. It was completed by 1975, almost 300 years after it was destroyed in an earthquake. The temple was almost entirely rebuilt using its original stones, except the missing pieces which were filled with blank stones intended to be easily recognisable. In 1978 a monument dedicated to Sahinian was erected not far from the temple.