Petrified Sea Gardens, also known as Ritchie Park, is a National Historic Landmark near Saratoga Springs, New York. It preserves an area of ancient stromatolites in a Cambrian rock layer. Stromatolites "were first recognized, discovered, and interpreted in North America" here, on property owned by Robert F. Ritchie, a stonemason and amateur geologist, who detected them in 1922 and opened a park to show them to the public in 1924. The site was a childhood inspiration for Stephen Jay Gould who went on to become "one of the most famous paleontologists of the twentieth century".