Not too long ago in England’s Grisedel Valley, about an hour’s walk from the nearest town, the hills gave way to a red bridge. It was small–just large enough to allow a few people to cross a creek.

Build a bridge that can hold rocks with your child. One at a time, place rocks in the center of the paper and observe how many rocks the paper can hold before it falls. Ask your child what he thinks ...

Out of all the materials you could choose to build a bridge, paper is probably not top of your list. But that didn’t stop artist Steve Messam from erecting one over the top of a valley in the Lake ...