Persa's house is a nice cave in the colored Oia. We didn't met Persa so we had to find the place into the tiny typical ways of Oia, between a lot streets and steps, helped from her map and from local people: nice and friendly.
My girlfriend and I found the house very nice and with a breathless view on the caldera. On the other hand it's a cave, so if someone has problems with humidity maybe it's not the perfect solution for you and your clothes.
The bathroom is essential: a little problematic if you're tall as in my case especially in the mornings :)
The kitchen is basic (the coffee pot was a little bit dirty) and the bed comfortable.
To sum up is the perfect place for who requires an astonishing view but not to much house comforts.