The first video features a retired Frenchman who bought and now resides in a house built in a cave in the Loire region of France. Throughout this video, (thanks the English subtitles), we learn about the history of this structure and its former occupants. I guess "caveman" takes on a new meaning here. Enjoy!
https://www.youtube.com/watch?v=DSbQ3t-j41Y
Image of cave house from Google images
This is not the house in the video.