The longest (and most expensive) bridge in the world when it opened in 1936, the Bay Bridge was first proposed by self-proclaimed "Emperor Norton I" in 1869.
This sign, designed by neon artist Betty Willis and erected in 1959, has become a world-famous symbol of Las Vegas. It was added to the National Register of Historic Places in 2009.
These tar pits hold the fossils of Ice Age animals that became trapped in the asphalt deposits here. The fossils were first described by Wellesley College professor William Denton in 1875.
Opened in 1892, Ellis Island served as a federal immigration station for more than 60 years until it closed in 1954. Millions of newly arrived immigrants passed through the station during that time.
The Gateway Arch, also known as the Gateway to the West, is the tallest national monument in the U.S. Construction began on Feb. 12, 1963, with the last section put into place on Oct. 28, 1965.
This park comprises 178 nautical square miles of seagrass beds, coral reefs and mangrove swamps and is the first undersea park in the United States.
Christ Church was founded in 1695 as the first parish of the Church of England in Pennsylvania, and the original church on this site was a simple structure.
