Cleft Ridge Arch, unknown date.

Completed in 1871, Prospect Park's Cleft Ridge Arch is a small béton-Coignet bridge that is celebrated as the first concrete arch to be built in the United States. The slabs used to build the archway were amongst the first concrete products to be mass-produced. When a financial “panic” came upon the country in 1873, the builders of Prospect Park shifted to alternative construction materials.

Sitting directly in front of the park’s Camperdown Elm, the Arch was fashioned from molded blocks of concrete that were comprised of sand, gravel and Portland cement. Today, the Arch is crossed by Wellhouse Drive, connecting paths to the Lullwater and Music Grove area.