The Karoo Sea — this is swampland on a giant scale. Teeming, pushing, living, scrambling forest grows riotously along the muddy banks of lagoons and stinking back swamps. Trees, club mosses, cycads and ferns compete for space, water and light, while those that have seen their days out collapse back exhausted to the forest floor, to be rapidly colonised by fungi and bacteria. Beetles scramble through the leaf litter or fly in an ungainly way through the canopy, while cockroaches scuttle and scratch in the leaf mould. But now we need to step back a little and look at the geological processes which have led to this change of circumstances. We have looked at the great ice age known as the Dwyka glaciation of 300 million years ago, but now we must take our focus off KwaZulu-Natal for a short time and look at what was going on in South Africa as a whole.