Nissyros (Nysiros) Volcano Photo Gallery While staying on the Greek island of Kos (also an ancient volcano) in 1996 I made a one day trip to Nissyros (also spelled Nysiros ) volcano. This 6 km diameter volcanic island is part of the Dodecanese Islands. Apart from the villages of Nikia, Pali and Mandraki most interesting feature is the 4 km wide caldera. The caldera was formed after the magma chamber imploded. Violent earthquakes and steam blasts accompanied the most recent hydrothermal eruptions in 1887. Inside this caldera a 250m wide circular depression can be found. This pit can be entered but you need good shoes and lots of water. The ground is a blistering 50°C, there is no wind and it smells sulphurous. What an experience!   Caldera wall Nissyros Volcano, Greece 1996   Walking down the pit I Nissyros Volcano, Greece 1996   Walking down the pit II Nissyros Volcano, Greece 1996 Smell the sulphur Nissyros Volcano, Greece 1996   Boiling water on hot surface Nissyros Volcano, Greece 1996   Sulphur crystals Nissyros Volcano, Greece 1996