Nissiros with an area of 41,6 square kms and coastine of 28 kms, is situated at the centre of the Dodecanese island complex. It lies between the islands of Kos and Tilos and the promontory of Knidos of Asia Minor. Nisyros has an almost circular shape and thereofore its coastline is not rich in geophysical formations. It is comprised of mountains which have originated from volcanic activity while the huge volcanic caldera, of length 2400 m and width 950 meters, situated at the centre of the island attests to its volcanic past. The visitor will admire from close the impressive craters the largest of which has a diameter of 260 m and a depth of 30m. Thermal springs are found at many points on Nissiros, themost well known of which are located a short distance from Mandraki. The capital of Nissiros is Mandraki which boasts, whitewashed houses, colourful narrow lanes and the beautiful piazza 'Ilikiomeni' (the old woman's piazza) which is shaded by large trees.

There are two weekly scheduled departures from Piraeus to Nissiros year-round. Travel time from Piraeus is approximately 16 hours.

In the summer there are tourist boats on a daily basis that go to Nisiros via Kos and Kardamena (Kos). From Rhodes there are flying dolphins (speed ferries only for passengers-no vehicles), catamarans and boats.