One of the two volcanic islands in the middle of Santorini Caldera. The water there has a temperature of about 33 Celcius and it contains sulfur that is good for the skin.
Ammoudi port can be reached by car (you have to circle round the bottom road of Oia village), by walking down the 235 steps, or by catching a ride on the back of a mule. At the bottom is a small harbour with fishing boats, waterfront amazing fish taverns and restaurants, and a path that leads you around the base of the mountain to an excellent diving area.