Ancient Iranian Cliff Architecture Still Utilized as Homes

I don't know much about these images, but the architecture pictured here is apparently 700 year old dwellings in Iran that have been carved into the side of a mountain. I love the fact that they are still utilized as homes to this day... With doors, windows and electrical cables fitted into the openings in the rock. If anyone knows more than I do about this architecture, please comment. I would be happy to update the post with more information.