The northern lights are brighter this year. Scientists explain why
Solar activity is peaking, and a quieter sky is letting more of us see it.
Fjords without the crowds: the slow way through Norway
Skip the cruise ships. Ferries, trains and a borrowed kayak tell a better story.
The megacity census: who really lives in the world’s biggest cities
Official counts miss millions. A new survey tries to find them.
After midnight: how cities are rethinking the night economy
Mayors are appointing night-time champions to keep cities open after dark.
The rooftop gardens cooling Europe’s old towns
Green roofs are turning hot terraces into the coolest streets in town.
Canal cities race to adapt as the water keeps rising
From floating homes to sponge streets, the old trading towns are adapting fast.