The fortification at Garni was erected probably some time in the 3rd century BC as a summer residence for the Armenian Orontid and Artaxiad royal dynasties.

Later, around the 1st century AD, the fortress of Garni became the last refuge of King Mithridates of Armenia, and he and his family were assassinated there by his son-in-law and nephew Rhadamistus.

Turning left leads along the river, past a fish hatchery, up to the Khosrov State Reserve and, a little further, Havuts Tar Monastery (which can be seen from the Garni temple).

The medieval bridge was controversially reconstructed in 2013, in a project organized and paid for by the US government through its Ambassadors Fund for Cultural Preservation.

Garni lies along the road to the UNESCO World Heritage Site of Geghard Monastery (a further 7 km southeast).