Around 12,000 years ago, as the Ice Age finally thaws, humanity makes a dramatic shift - abandoning nomadic life for permanent settlements.
In Turkey, Ella Al-Shamahi visits the world's oldest temple, Gobekli Tepe, and one of the largest early towns, Catalhoyuk - a prototype in urban living, with no streets and honeycombs of dwellings accessed through the roofs. But living in densely populated towns, with livestock alongside them and dead ancestors buried beneath their houses, brought new challenges: disease and evidence of unrest and brutal violence.
In Egypt, Ella finds out how cities began to thrive rather than collapse. And in a turquoise mine in the Sinai desert, she discovers how migrant workers were responsible for creating the first alphabet.
