1. Kalymnos: Since ancient times, Kalymnos has been known as the "sponge-divers' island". Its brave divers collected natural sponges from the sea, which were the main source of income for the local families, all the while bringing wealth and fame to the island. The island's landscape is rocky, partly a reason that the island has also evolved into a worldwide rock climbing destination. The island is connected to Kos through high-speed boats (catamarans) and is ideal for a day trip. Kalymnos is among the three destinations of the three island cruise itinerary (Kalymnos, Pserimos, Plati), and therefore can be visited easily and hassle free.
2. Nisyros: The island of Nisyros offers the once-in-a-lifetime opportunity of walking on an actual volcanic crater. In fact, the volcano in Nisyros is one of the more active but less known volcanoes in Greece. The last volcanic eruptions in 1881-87 formed a moonscape with colourful craters and very active fumaroles, the location of which is today visitable. The island is often described as an alternative one, because it features one of the favourite beaches among free-camping enthusiasts in Greece. Perfect for a day trip starting from Kardamena.
3. Pserimos: Probably the most popular island hopping destination on Kos due to its small distance from the island (7.8 nautical miles). The tiny island belongs to the administration of Kalymnos and is a destination on the three island cruise itinerary (Kalymnos, Pserimos, Plati), a day trip offered from the main harbour of Kos.