Póas was the first volcano I ever saw. It's in Costa Rica; a little north of San Jose, the capital. This is a painting of the bottom of the crater and the acidified lake at its center. The landscape there is an amazing gray desert of ash and lava rock, broken by slashes of vivid color caused by mineral salts dissolved in the water and evaporated out on the rocks. The effect is rather like a charcoal drawing with splashes of gouache color on it.