Rivers can sometimes feel like surface-level details, but it's surprising how ancient they can be. One of my favourite geographical factoids is that the Amazon

Rivers can sometimes feel like surface-level details, but it's surprising how ancient they can be. One of my favourite geographical factoids is that the Amazon and the Congo are thought to have once been part of the same river system in the supercontinent of Pangaea more than 100 million years ago, with the Amazon part then flowing east to west and emptying into the Pacific.