The walls of America's oldest masonry fort famously "swallowed" cannonballs.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

Meet manatees face-to-face at this zoo for native species.

Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

This small museum gives visitors a chance to soak up the history of the "sponge capital of the world."

Island ghost town detailing Flagler's folly in building the Overseas Railroad.

"We Seceded Where Others Failed."

A monument celebrating the idea of reaching inaccessible places.

The highway's southernmost spot is a beloved local attraction.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

I-95's Tijuana-style celebration of kitsch at the Carolina border.

The remains of a chapel created for convenience.

One of the oldest living oak trees in the Southeast.

This recently rediscovered Civil War-era submarine was the first to ever sink an enemy ship.

Oldest unrestored plantation house in America that is open to the public.

The 340-year-old house that inspired the classic Nathaniel Hawthorne novel.

Experience the hysteria of a 17th century witch hunt through goofy reenactments and wax dummies that should probably be burned at the stake.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

One of America's most historic homes also holds a startling literary legacy.

This small section of the Sleepy Hollow Cemetery is rotten with famous authors' graves.

Louisa May Alcott based “Little Women” on her experiences growing up in this house with her sisters.

The Wright Tavern is possibly the most important building in Concord Massachusetts to the American Revolution.

"the sweltering inhabitants of Charleston and New Orleans, of Madras and Bombay and Calcutta, drink at my well . . . The pure Walden water is mingled with the sacred water of the Ganges."

This nearly 200-year-old restaurant's history includes an exiled French prince, JFK, and a very hungry Daniel Webster.