Most of the 17,000-strong population of Kálymnos lives in or around the large port of Póthia, a wealthy but not conventionally beautiful town, famed for its sponge industry. Unfortunately, almost all of the eastern Mediterranean's sponges were devastated by a mysterious disease in 1986, related to freak warm currents, and only three or four of the fleet of thirty-odd boats are still in use. In response to this catastrophe (and a smaller repeat outbreak in 1999), the island established a tourist industry - confined to one string of beach resorts - and also retro-fitted most of its sponge boats for deep-sea fishing. Warehouses behind the harbour still process and sell sponges all year round, though most of these are imported from Asia and the Caribbean. There are also still numbers of elderly gentlemen about who rely on two canes, walking frames or even wheelchairs, stark evidence of the havoc wrought in their youth by nitrogen embolism (the "bends"), long before divers understood its crippling effects. The departure of the remaining sponge fleet, usually just after Easter, is preceded by a festive week known as Yprogrós , with food, drink and music; the fleet's return, approximately six months later, has historically also been the occasion for more uproarious, male-oriented celebration in the port's bars.

 

Kálymnos essentially consists of two cultivated and inhabited valleys sandwiched between three limestone ridges, harsh in the full glare of noon but magically tinted towards dusk. The climate, especially in winter, is alleged to be drier and healthier than that of neighbouring Kós or Léros, since the quick-draining limestone strata, riddled with many caves, doesn't retain as much moisture. The rock does, however, admit seawater, which has tainted Póthia's wells; drinking water must be brought in by tanker truck from the Vathys valley, and there are also potable springs at Dhámos, Potamí district of Póthia and Hóra.

Since Kálymnos is the home port of the very useful local namesake ferry, a minor hub for Kyriakoulis Maritime hydrofoils, and moreover where the long-distance ferry lines from the Cyclades and Astypálea join up with the main Dodecanesian routes, many travellers arrive unintentionally, and are initially most concerned with how to move on quickly. Yet Kálymnos has sufficient attractions to justify a stay of several days while island-hopping - or even longer, as the package industry at the western beaches suggests