Built as a fort to defend New York Harbor during the war of 1812, this national monument has played numerous roles, including opera house, entertainment complex and aquarium. It's now a visitor center, with historical displays (including an interesting timeline documenting New York's growth), a ticket booth for ferries to the Statue of Liberty and Ellis Island, a gift shop and restrooms.
The circular structure got its current moniker in 1817 to honor then-mayor DeWitt Clinton. Later, and before Ellis Island opened to immigrants, Castle Garden (as it was then known) served as the major processing center for new immigrant arrivals, welcoming more than eight million people between 1855 and 1890. Rangers lead free historic tours of the site daily at 10am, noon, 2pm and 3:30pm, subject to staff availability.
