My stay at Maria’s cave house was truly one of a kind. Her host Eleni was extremely accessible by message and when I arrived helped to coordinate a driver to take me to the flat, and then meeting me where is the driver dropped me off with someone to take my luggage down to the flat. When there was a miscommunication upon my first arrival, Eleni made sure to make it right and was extremely gracious. She provided great recommendations and was always available by text.
One thing you should know is that the bathroom is outside the flat, as others have noted, so that means using the shower or toilet you must go outside and walk a few steps to the bathroom, not really an issue. Another thing to note is that caves are a bit musty so there is a dehumidifier that runs all the time, and I did have to use the fans at night to help cool down, but then as the night goes on the cave temperature does drop. The space is very beautiful, The bed comfortable (I did not sleep in the far back) and unique, and has one of the best locations, right next to the famous two dome church and photo spots. Yet it’s just far enough removed that the crowds disappear. But beware there is a lot of steps down to the apartment, but so is everything in Santorini so no matter what you book you will have to climb.