It is well known that before the famous eruption of August 1883 took place, the island Krakatoa consisted of three volcanoes, the basaltic volcano Rakata and the andesitic volcanoes Danan and Perbuwatan. With the great explosion of August 28th of that year Danan, Perbuwatan and the northwestern part of Rakata were entirely destroyed. Since then a coral reef began to grow on the Northwestern slope of the Rakata ruïn at a spot called Black Point (Zwarte Hoek), a place where the basaltic lava of Krakatoa is exposed.