Khor Virap translates loosely as "deep pit" and is one of the most significant historical sites in Armenia. Gregory the Illuminator, the figure who introduced Christianity to Armenia, was imprisoned in the eponymous pit for 13 years after King Tiridates found out he was Christian. The King eventually fell ill and his sister received a vision that Gregory could heal him if he were released from the pit. Gregory successfully cured the King of his temporary madness and Armenia subsequently became the world's first Christian nation, prior to the practice of Christianity even being allowed in the Roman Empire, in the year 301. The pit itself still exists below the complex and you can descend into it to experience a bit of Gregory's isolation.