(graphic borrowed from A Most Curious Planet)
Here's a great slide show in The Telegraph from Dan Cruickshank's new book, Bridges: Heroic Designs that Changed the World.
No, the above photo isn't one of them. I borrowed that from elsewhere on the internet.
But the 12 photos in the slide show are well worth viewing. I also enjoyed hearing of "the Devil's Bridge," a name apparently given to many bridges in medieval Europe, because the local people "could not believe such constructions were built by human hands."
These days, they'd probably give the credit to aliens, huh?