Youngstown (New York)

A full accounting of the history of fortifications at this site could fill a small book. Suffice it to say that the location on a promontory at the point where the Niagara River empties into Lake Ontario was a vital strategic location until well into the nineteenth century. The famed "French Castle" that forms the centerpiece of the modern attraction was built in 1726, making it the oldest building in the U.S. between the East Coast and the Spanish Southwest. During peak season, you'll see artisans, artillery and musket demonstrations, and tour guides; the rest of the year, you'll be relying on self-guided and audio tours to view the structures—though you'll still see hourly musket demonstrations. Some special events feature re-enactors populating the fort.