I stayed at Caveland for a month, and I loved every second of it. I rented a private room inside one of the caves, and it came fully equipped with a mini-fridge, a small oven, and a private bathroom.
But what I loved the most about this place was its atmosphere. There were endless nooks and crannies to explore. The pool and poolside bar open in the summer months, but there's a lounge area and an open courtyard to hang out in year-round.
Karterados is about a 25 minute walk from Fira, but there's a bus stop at the top of the hill. Plus there are a dozen of restaurants and shops nearby, including ATV rentals, and at much lower prices than near the busy island's center.