Modern bridges are often things of beauty and awe. The Milau Bridge in southern France is a wonder. The Erasmus Bridge in Rotterdam is rightly nicknamed "the Swan," while the Ling Tie is just stunning.
But ancient bridges started it all and many Roman ones taught the world first how to build them. The Alcántara Bridge near the border of Portugal and Spain is an excellent example.
This elegant wonder arching over the Tagus River was completed in 106 AD and — amazingly — is still in use. It has several times been damaged by wars (particularly during the Napoleonic Era), but never completely destroyed. Made of granite, it spans over 190 meters (640 feet) and rises more than 70 meters high.
It's something of a pity that Julius Caesar is better known than Caius Julius Lacer, the bridge's designer, but it has always been thus. Conquerors invariably get more attention from historians than creators. Maybe someday that will change. In the meantime, enjoy the view.