The main building of the monastic compound is Surp Astvatsatsin (Holy Mother of God) church. The exact date of the building of the church is unknown. It is generally regarded as an 11th-13th century complex, but the current church has been built on an earlier foundation. Kirakos Gandzaketsi mentions that
Ivane Zakarian was buried in the church in 1227.
Stepanos Orbelian refers to the church in 1216. Modern researchers date the murals within the church to 1205–1216. Princess Mariam, the daughter of
Gurgen II (Kyurikeh II) made a record in 1188 on the back of a
khachkar found in a place called Ayor adjacent to Akhtala which refers to the construction of the Holy Mother of God church at Akhtala. The inscription on the khachkar states the following: "I, the daughter of Kyurikeh, Mariam, erected Surp Astvatsatsin at Pghndzahank, those who honor us remember us in their prayers." In 1185 Mariam had constructed the
narthex of the main church in Haghpat. According to some local lore, the church was built in the 7th century by Byzantine emperor of Armenian extraction,
Heraclius. Another legend assumes that the church was built in the 5th century by Georgian King
Vakhtang I Gorgasali. There is no reasonable evidence to support either story. The church used to contain the cross which according to
folklore was used by
John the Baptist to baptise Jesus Christ. Vasak, the father of Prince Prosh, is said to have given this relic to Ivane Mkhargrdzeli who later sold it for a large sum to the monastery of
Noravank in
Syunik. The church is situated in the middle of the fortress' territory along the longitudinal axis. It belongs to the domed basilica type of churches, where the bearings join with the side-chapels of the apse. Two pairs of arches divided the longitudinal stretched prayer hall into three naves, the central one of which (with double side-chapels) on the eastern side ends with low staged, half-rounded apse and the side-chapels end with sacristies. They are characterized with stylish iconography, richness of theme and variety of different colors (where blue is dominant). The vertical axis of the building was crowned by a massive dome. The pointed dome with the cylindrical drum has not survived. It was damaged during Tamerlane's invasion and completely demolished in 1784 when the
Avar Omar Khan invaded the
Transcaucasus from
Dagestan. In the 19th century,
Viceroy of the Caucasus, Prince
Mikhail Vorontsov built a semi-spherical wooden dome covered with iron sheets in place of the original dome. The dome was renovated during Soviet years. ==Murals of Surp Astvatsatsin==