Now the sun had risen we returned our attention to the crater floor. Over the years since the last eruption, Ol Doinyo Lengai’s crater has slowly been filling with lava. This does not mean that there is a big old pool of bubbling red and yellow firey rock liquid. The lava cools and forms a crust, as pictured here. I believe that in some places this crust might we quite thin, disguising a dangerously hot (520ï¿½C) core of molten lava. This can be rather dangerous. I was glad to have a stick to test the ground I was walking on. After reading the page linked to above, I wish I had some leather shoes!