At the trail bottom the rainforest parts revealing a vast open plain. The crater is approximately two and a half miles wide east to west. Receeding lava, which courses just a few hundred feet below the surface, has caused the crater floor to slump and crack in some places. Through these cracks plumes of steam arise and are cast on vagrant breezes. Heat trapped in the crater and the relentless equitorial sun make water a valuable commodity here in spite of the nearness of the rainforest.