The Netherlands is one of the flattest countries in the world. There are barely any hills, so cycling is easy almost everywhere. The weather is often cool and damp, so a bike ride doesn't make you too hot. And the cities are close together, so most places you'd want to go are only a short ride away.
Bike paths in the Netherlands are not just painted lines on the road. They are separate little roads of their own, often painted red, with their own bike traffic lights. Children as young as four or five start cycling on them with their parents. By the time they are eight, most Dutch children cycle to school themselves.
In Utrecht, there is the biggest bike park in the world. It is underground, near the train station, and can hold 12,500 bicycles - one of every kind you can imagine. People drop off their bike, hop on a train to work, then come back at the end of the day and pick it up again.
Dutch schools teach a special cycling test in Year 4 or 5. The children ride a route through real streets, with examiners marking how well they signal, stop and steer. If they pass, they get a certificate - and the right to cycle to school by themselves.