Kostas' Windmill is absolutely perfect!
I've spent there a week with my husband and some friends (we were 3 couples) and we enjoyed the place so much!!
The house is totally Greek, a renovated ancient mill, with three spacious rooms, each one with a nice toilet. There is also a comfortable outside and the place is very quiet, but also not far from beaches and the city of Emporeio.
The view is unbelievable: you can see the sea in two different direction and the sunset is very romantic!
Kostas is the perfect host, very kind and friendly. He helped us to find bikes, with transports in general and he gave us nice tips on the Santorini's life.
I recommend warmly the Windmill to a group of friends or a family: you will be very happy there!!