An ancient city used rooftops as its only streets

The 8,000 residents of Çatalhöyük lived in a city that looked more like a giant honeycomb than a modern town. Because the mud-brick houses were built directly against one another with no gaps for streets, the only way to move through the city was to walk across the flat roofs. Residents entered their homes through a hole in the ceiling, descending a wooden ladder into a central living space that served as kitchen, workshop, and shrine.