Katerina's house was a unique experience that we really enjoyed. She did call it a cave house, but I did not fully understand that it is literally an entire house built into a hillside! It has stone walls / floors / ceiling, with windows up front. The surrounding houses are the same, as this appears to be an enclave that decided to make cave houses. A great side effect of this is that you do NOT need AC! Even during our summer visit, it was nice and cool in the house, to the point where we turned on a heater to be comfortable. The cave is naturally humid, but Katerina has a good dehumidifier to address that issue. It is NOT from the stone ages, but rather is as modern as any other "classic" house, and of course has WiFi. We enjoyed our visit there!