"A hundred years ago our view of space and time was dramatically changed by the introduction of special relativity. Ten years after that, Einstein made spacetime dynamical in his general theory of relativity. It has long been expected that quantum gravity will require an even more radical change in our view of spacetime. String theory is a promising approach to a consistent quantum theory of gravity. In the past few decades a new picture of spacetime has been emerging from this theory. While this picture is far from complete, it is already clear that spacetime has many different features than it does in relativity."