Located on the Sacramento River is the Sundial Bridge. Redding commissioned world famous Spanish architect, Santiago Calatrava (architect for the Athens Olympic Stadium) to design a pedestrian bridge over the Sacramento River, linking the Turtle Bay Exploration Park’s museum, to its Arboretum and Gardens, and as a trailhead for Redding’s extensive Sacramento River National Recreation  trail. One of the design criteria given Calatrava, was to design a bridge that would not impact the nearby spawning grounds for the winter run of Chinook salmon. The 710-foot-long bridge spans the river without footings in the water. Its walking surface is translucent glass, so as not to cast a dark shadow on the spawning gravels below the bridge. This design achieved this goal with an inclined 21 story tall pylon built on the north bank of the river that supports the entire river span. Also, because of the exact north-south orientation of the bridge, the pylon serves as the upright element of a sundial, making it one of the worlds tallest Sundial.