Long famed as one of the best beaches in Greece, remote Egremni was devastated by an earthquake in 2015. Both the road that ran to the clifftop above it and the 720-step stairway down to the beach were obliterated and are unlikely to be rebuilt. Now the only way to see what’s left of Egremni, and to bathe in its magical turquoise waters, is to take a boat excursion from elsewhere on the island.