Saint Thaddeus Cathedral in 20 km northeast of Chaldoran, in the West Azerbaijan province, is the oldest and first Christian cathedral, which was built on the tomb of one of the apostles of Christ, Thaddeus. According to its unique architecture, this historical and religious monument is registered in UNESCO World Heritage site along with Saint Stepanos monastery in Jolfa and Dzor Dzor chapel in Maku

Saint Thaddeus is also famous as Qareh Kelisa due to the meaning of Qareh as ‘black’ in the Turkish language. In fact, because of the use of black stone in some parts of its facade, this building has taken the name of Qareh Kelisa. What makes this building different is the use of bricks in two colors, white and black which refers to the many reconstructions of this church. The last reconstruction of Saint Thaddeus dates back to the Qajar period, when Abbas Mirza, the son of Fath Ali Shah ordered that a new section made of white brick be attached to the old part of the church in order to rebuild it in the style of Armenian churches.

Saint Thaddeus is highly sacred among Armenians and during the first week of Mordad (early July), Christians from Iran and other countries such as Armenia, Netherland, France, Austria etc., participate in a religious ceremony in memory of the martyrdom of Thaddeus. This ceremony is the biggest religious ceremony in Iran for religious minorities. Thus, this prominent event is registered in UNESCO’s Intangible Cultural Heritage.

Historical significance as well as the geographical location of Saint Thaddeus Cathedral makes it one of the most noteworthy tourist attractions in Iran. Additionally, the spiritual atmosphere of this church ensures a memorable experience for any visitor.