Petrified Sea Gardens
The Petrified Sea Gardens is the site of one of the best examples of stromatolite fossils in the world. Stromatolites are the fossilized structures of 1-2 feet tall algae colonies and other life forms that once existed in shallow tropical waters during the Cambrian period, about 515 million years ago (at that time, what is now North America was further south in the equator). The stromatolites were later "planed" by glaciers, revealing the circular structures in which they were formed. The site was was placed on the National Register of Historic Places and designated a National Historic Landmark in 1999. It is also a National Natural Landmark.
Backstory and Context