The fortress of Garni was a mighty fortress well known from chronicles (Cornelius Tacitus, Movses Khorenatsi, etc.). It was built on a cape-in naturally defended place. The structures of Garni combine elements of Hellenistic and national culture. The summit of the cape was crowned with a temple which overlooked the square by its main northern façade.

The temple, the artistic center of the complex, is on the central axis passing through the fortress gate. It was built in the second half of the first century B.C. and dedicated to a heathen god, probably to Mithra (Mihr in Armenian), 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 palace complex included several disconnected buildings situated around the vast main square of the fortress, in its southern part, away from the entranceway, where they formed all ensemble. Except the temple the complex included a presence chamber, a columned tall, a residential block. a bath-house.