The iconic Gateway Arch was inspired by the natural curve of a hanging chain, a catenary curve. Curves also shape the surrounding landscape, appearing in the gentle arc of the tree-lined paths and staircases, the graceful sweep of the retaining walls, and the flowing ribbon of the ponds' edges. The Gateway Arch is 630 feet high and 630 feet wide at its base, and a chain hangs from two points in an inverted arch shape.