A cave whose roof breaks the surface while its floor drops away underwater, so you swim from daylight into a chamber lit from…A cave whose roof breaks the surface while its floor drops away underwater, so you swim from daylight into a chamber lit from above. Around it, Kalymnos' walls, ancient amphora scatters, and the sponge-diving heritage that defined the island. The limestone cliffs above hold some of the best sport climbing in Europe. Kalymnos was the sponge-diving capital of the Mediterranean, and its divers paid a terrible price, the primitive Fleuss and standard-dress suits crippled generations with decompression sickness, a history the island's museum documents unflinchingly. The sponge fleet died with synthetic sponges in the 1980s. Anchorage: Anchor in Emborios or Vathy fjord, a spectacular narrow inlet on the east coast. Hazards: Overhead environment in the deeper cave sections; take a guide. Plus