The history of Vietnam is one of the longest continuous histories in the world, with a cultural history of around 25,000 years.[1] Archaeological findings from 1965, still under research, show the remains of two hominins closely related to Sinanthropus, dating as far back as the Middle Pleistocene era, roughly half a million years ago. Ancient Vietnam was home to some of the world's earliest civilizations and societies—making them one of the world's first people who practiced agriculture.[2][3] The Red River valley formed a natural geographic and economic unit, bounded to the north and west by mountains and jungles, to the east by the sea and to the south by the Red River Delta.