For most of human history, the great majority of people lived in villages and farms. That changed sharply with the Industrial Revolution, when factories drew workers into rapidly growing towns and cities. Over the 20th century, urbanisation accelerated across the world, and the United Nations estimates that the urban population passed the rural one around 2007. Today the largest share of humanity lives in cities, though the pace differs widely between regions. Some countries are almost fully urban, while much of Africa and Asia is still urbanising quickly. Cities concentrate jobs, services and ideas, but they also bring pressure on housing, transport and the environment.

Israeli reports also say the cabinet directed the military to prepare for a possible new attack on Iran.

Angkor, near Siem Reap in northern Cambodia, was the capital of the Khmer Empire, which ruled much of mainland Southeast Asia between roughly the 9th and 15th centuries. At its height the city spread across about 3,000 square kilometres, making it the largest pre-industrial city on Earth by area. Its growth depended on water: huge reservoirs called barays, along with canals and embankments, stored monsoon rain and carried it to rice fields. That system let farmers harvest more than once a year and fed a very large population through the dry season. The temple complex of Angkor Wat, built in the early 12th century, is the best-known monument and still stands at the heart of the park.