This is an active volcano in Colombia, with two major fumaroles. The vents, one metre across, emit sulphur in jets of very hot air, making a tremendous noise. Its summit is ice-free and yellow with sulphur.
Our itinerary first took us right to the centre of the crater, where a number of huge volcanic chimneys are temporarily dormant. Another 200m up took us to the edge of the crater: the summit.
A few Indian families make their living from the volcano, collecting sulphur and ice there. It’s extremely hard work.