Sierra Negra is the second largest active caldera in
the world, the first being Yellowstone. This photo was taken
standing on the lip of the crater looking out over the lava field.
There is no vegetation because the lava was renewed just ten years ago at
the last eruption, where a new crater formed on the north side and the
lava flowed out from that across the plain.
To give you an idea of the size of this volcano, you
can just see the crater wall in the distance,
which is about ten miles