This megacity is growing relentlessly and is not for the faint of heart. Anyone wanting to experience China simply cannot miss Chongqing – the largest city in the world.

Mexico City was once feared; today, the megacity is a tourist hotspot. The city has retained its fighting spirit – in some places for the sake of spectacle, in others for survival.

Lagos is growing faster than any other city in the world. A megacity of extremes: while many of its 25 million inhabitants live in poverty, money is no object in its clubs.

Extraordinary people, touching stories and mysterious places.

As night falls over the Thames, those sharp contrasts emerge that make London arguably the most interesting and international metropolis in Europe.

Rio de Janeiro is Sugarloaf Mountain, the Christ the Redeemer statue, and Copacabana. When night falls, culture and music pulsate – but it's also hard work in the "engine room" of the metropolis.

Between tradition, chaos, and constant upheaval: How does beleaguered Istanbul, with its 16 million inhabitants, manage to survive as a modern global city despite all the tensions?

Vienna is beautiful. Framed by the facades of the Austro-Hungarian era, people enjoy culture and coffee, clattering past St. Stephen's Cathedral and the Sisi Museum in horse-drawn carriages. Until night falls.

When pilot Ky sees the Toronto skyline during her evening approach, it's the happiest moment of her day. The financial metropolis transforms into a vibrant, dazzling melting pot.