Looking south into Red Crater. Ngaruhoe beyond. Photo NC.

Ash eruptions have occured here in 1897 and 1926, and Red Crater is still considered active. Currently the only signs of activity are steam fumeroles at various locations, near the summit as well as lower down in the area of the Emerald Lakes.
A distinctive feature of Red Crater is the dyke visible here near the centre of the picture. More generally the vivid colours and strange shapes displayed in this area make it one of the highlights of the Tongariro Crossing.
At 1886 m (6187') this is the highest point of the whole walk (unless complemented by a side trip to the summit of either Ngaruhoe or Tongariro).