Electricity powers the life support systems that keep cities running, from lights to communications. Without it cities would stop working and lives would be at risk.
Food is a city's most important source of energy, and without new supplies they will run out of fresh food in a matter of days. Learn how cities master replenishment.
As cities become more crowded, architects and builders face a constant challenge: how to create new spaces in cities where every plot has already been developed?
Transport links are a city's veins and arteries and if they're cut-off the city will die. It's an endless task demanding brain and brawn, but how is it carried out?
For centuries cities have been built near a fresh water supply. And with every passing year the challenge of providing water to billions of people becomes more complex.