Originally established in 642 CE, the Khor Virap (Armenian for "deep dungeon") Monastery did not take on its current and final incarnation until the 17th century, but even before its founding the former prison site was notable for holding the man who would become Saint Gregory the Illuminator in a pit for 13 years before he helped turn the country into the first Christian nation.

Before attaining sainthood, Grigor Lusavorich was held in a cell at the bottom of pit dug into an Armenian hillock. For 13 years the man survived by being secretly fed by local Christian women. Then, as the story goes, Lusavorich cured the ruler, King Trdat III, of a disease (either madness or more mythically from having the head of a boar) and subsequently converted the monarch to Christianity. As the king went, so went Armenia and soon the country was the first officially Christian nation in the world.

After Lusavorich was sainted as Gregory the Illuminator, the hill in which he was held for so many years became a popular holy site. The first church sites were constructed on the lone elevation beginning in 642, and have been repeatedly rebuilt since. The iconic Surp Astvatsatsin Church which stands on the site today dates from the 17th century. Despite centuries of architectural turmoil, the pit where Saint Gregory was incarcerated can still be visited through the hole to the right of the altar in the St. Gevorg Chapel. The cell is located at the bottom of a claustrophobic, and clammy 200-foot descent by ladder. The dungeon itself is a wide circular room about 14-feet wide and is outfitted to look like it might have when St. Gregory was held there. 

Khor Virap Monastery continues to be a holy site of the Armenian Apostolic Church and an important pilgrimage location which locals often visit for a baptism or after a wedding to perform a "matagh" or "sacrifice," often of sheep or chicken. The walled, religious complex also stands before the snowcapped flanks of Mount Ararat, offering a spectacular view of the mountain and cutting a striking silhouette in and of itself.