The temple was built in the second half of the first century B.C. and dedicated to a heathen god, probably to Mithra, the god of the sun whose figure stood in the depth of the sanctuary (naos). After Christianity had been proclaimed the state religion in Armenia in 301, the temple was probably used as a summer residence of the kings. A chronicle describes it as ‘‘a house of coolness’.
The fortress of Garni is situated in the village of the same name in the Abovian District. That was a mighty fortress well known from chronicles (Cornelius Tacitus, Movses Khorenatsi, etc.). The structures of Garni combine elements of Hellenistic and national culture, which is an evidence of antique influences and the distinctive building traditions of the Armenian people. The artistic merit and uniqueness of its monuments place Garni among outstanding creations of architecture of world importance.
The structures of the fortress of Garni are in perfect harmony with the surrounding nature. The fortress is situated in a picturesque mountain locality and commands a broad panorama of orchards, fields and mountain slopes covered with motley carpets of varicoloured grasses, of the jagged and precipitous canyon of the Azat river.
Source (Wikipedia)
Special Thanks to Serdal & Babken