Santiago Calatrava designed this footbridge as an enormous sundial. Completed in 2004, it's an international attraction for architecture fans.

The bridge as a cable-stayed structure, with a 217-foot-high gnomon built on the north bank of the river. The deck is made of nonskid glass panels, set in a steel framework. Developing the sundial theme, Calatrava made the gnomon hollow, so that visitors at river level can look up through it.