The Khor Virap (Armenian: Խոր Վիրապ, meaning "deep pit" or "deep well") is an Armenian Apostolic Church monastery located in the Ararat plain in Armenia, near the border with Turkey, about 8 kilometres (5.0 mi) south of Artashat, Ararat Province. The monastery was host to a theological seminary and was the residence of Armenian Catholicos.
Khor Virap's notability as a monastery and pilgrimage site is attributed to the fact that Grigor Lusavorich, who later became Saint 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 proselytizing activity 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 AD at the site of Kirat 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 probably the most visited pilgrimage site in Armenia.