The view from Rena’s cave is unbeatable - you look right out over the caldera while enjoying complimentary espresso each morning. The place is central in Oia and very easy to walk to the castle to watch sunset or to shops and restaurants.
The cave itself is so neat and authentic! I wouldn’t have wanted to stay anywhere else. That said you have to be okay with lots of stairs to get down to it (and they are sloping cobblestone stairs, not great for someone with any instability) and with the bathtub/handheld shower open in the bedroom, no privacy for washing up! Which was fine with us.
Overall we were just delighted with our choice to stay here and would highly recommend.