Khor Virap's notability as a monastery and pilgrimage site is attributed to the fact that Gregory the Illuminator was initially imprisoned here for 14 years by King Tiridates III of Armenia. Saint Gregory subsequently became the king's religious mentor, and they led the proselytizingactivity in the country. In the year 301, Armenia was the first country in the world to be declared a Christian nation. A chapel was initially built in 642 at the site of Khor Virap by Nerses III the Builder as a mark of veneration to Saint Gregory. Over the centuries, it was repeatedly rebuilt. In 1662, the larger chapel known as the "St. Astvatsatsin" (Holy Mother of God) was built around the ruins of the old chapel, the monastery, the refectory and the cells of the monks. Now, regular church services are held in this church. It is one of the most visited pilgrimage sites in Armenia.
Khor Virap is located on a hillock in Pokr Vedi; the village is 4 kilometres (2.5 mi) from the main highway. Yerevan, the capital and largest city of Armenia, is 30 kilometres (19 mi) to the north. It is situated about 100 metres (330 ft) away from the closed Turkish-Armenian border (sealed by barbed wire fencing) and defended by Russian military establishments that guard the troubled border zone.
The monastery is surrounded by green pasture lands and vineyards within the Ararat plain and is in view of Mount Ararat. The Arax (or Arakas) River flows close-by and the monastery is opposite of Aralık, Turkey. King Artashes I, founder of the Artashesid dynasty, established his Armenian capital at Artashat (also known as Artaxtisata) around 180 BC. It is believed that Hannibal, the Carthaginian General who was persecuted by Rome, was also instrumental in establishing Artashat. Artashat remained the capital of the dynasty till the reign of King Khosrov III (330–339) when it was moved to Dvin. Subsequently, Artashat was destroyed by the Persian King Shapur II. Artashat is close to the hillock of Khor Virap. Until its chapel was built, Khor Virap was used as royal prison.