Speaking about Nisyros
volcano, it literally means the whole island. But for tourists it means Stefanos - the largest crater in the heart of the island and the only one which officially accepts visitors. The volcano is defined as "dormant" - active but not erupting. Steam coming out of the holes can be seen on many places and the specific sulfur smell is everywhere in the air. Walking inside the crater is at your own risk (that is what the signs say) and the feeling that you step on a sleeping monster may be unpleasant to some people. Nevertheless, it is a thrilling experience.
The place is very easy to find. If you are not on an organized trip, there are buses leaving from Mandraki
to the volcano on regular schedule. If you are with a vehicle, there are enough signs to guide you. Next to the crater there is a large parking lot and even a cantina selling snacks, drinks and small souvenirs from the volcano. The crater is in the middle of a depression, surrounded by the caldera. Stefanos is about 25 high and 300 meters wide. The bottom center is fenced and there you can see rough holes with hot steam coming out of them. The surface in and around the crater is hot and thin soles may give you a burning sensation.
The landscape around Stefanos is barren and in close vicinity there are two more craters, Alexandros and Polyvotis. Unpaved road going along the crater will take you to the monastery of Stavros, at the rim of the caldera and with view toward the entire depression.