Tehran -- Three historical churches, dating back to different historical eras in the northwestern West Azarbaijan province, have undergone restoration, a provincial tourism chief has said.

Petrus Polis, Chamaki's Saint Merry and Nakhjavan Tappeh's Saint Merry churches due to their damages and destructions are being restored, CHTN reported Jalil Jabbari as saying on Tuesday.

Located eight kilometers to the east of the provincial capital of Urmia, in Klisakendi village, Petrus Polis Church was built in the 8th century. The church, which is considered one of the oldest Assyrian churches in the country, was inscribed on the National Heritage list in 2001.

Saint Merry in Chamaki village is also one of the oldest Assyrian churches in the region. Around 600 Assyrian populated the village, who speak in Modern Assyrian.

Saint Merry Church in Nakhjavan Tappeh, 22 Kilometers to the northeast of Urmia, was built in the 17th century and is still used by the Armenians living in the village.

Iran is home to several ancient and historical churches. Christians, Jews, and Zoroastrians are the most significant religious minorities in the country with Christians constituting the bulk.

West Azarbaijan embraces a variety of lush natural sceneries, cultural heritage sites, and museums including the UNESCO sites of Takht-e Soleyman and Qareh Klise (St. Thaddeus Monastery), Teppe Hasanlu and the ruined Bastam Citadel.

The region was a center of several ancient civilizations. According to Britannica, it was conquered by Alexander the Great in the 4th century BC and was named Atropatene after one of Alexander's generals, Atropates, who established a small kingdom there. Ultimately, the area returned to the Persian (Iranian) rule under the Sasanians in the 3rd century AD.