This monument is a stark reminder of the horrors of the Zanzibar slave trade.

In Zanzibar, a historic 19th-century palace is a reminder of the world's shortest war.

This slowly crumbling mansion was home to one of East Africa's richest and most powerful slave traders.

An exquisite and eclectic selection of African masks stands out within a massive woodcarving marketplace.

At this farm in upstate New York, the former president plotted his reelection campaign.

A small Second Empire-style building is one of only seven remaining lighthouses on the Hudson River.

The Hudson River School comes alive at this palatial estate.

The abandoned ruins of America's first private zoo are open for exploration in the Catskills.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

An abandoned 19th century quarry in the middle of the woods, remade by unnamed wanderers into a massive series of rock thrones.

Now the final resting place of prominent artists and musicians, it was originally founded to separate the rich from the poor in death.

A peaceful international sculpture garden in upstate New York.

A once grand hotel is being retaken by the wilderness it once capitalized on.

Ancient petroglyphs discovered only after a massive fire swept across Michigan in the 1880s.

An easy-to-reach, century-old shipwreck in shallow and crystal clear waters.

Turnip-shaped island just off the Michigan shore in Lake Huron.

Artist Scott Hocking took a dilapidated 1890s barn to create his massive "Barnboat."

This classic red schoolhouse is said to have been where Mary and her little lamb went to school.

This general store near Boston was once owned by Henry Ford, who had it relocated to a different town using a team of oxen.

This dam in the woods, built by Henry Ford with only manpower and oxen, holds no water and serves no purpose.

The oldest continuously-operated inn in the United States, once owned by Henry Ford.

In the middle of a New England forest sit the crumbling ruins of World War II-era ammunition storage bunkers.

Funded by John D. Rockefeller, this is one of the earliest, and most beautiful, shopping arcades in America.

Unique collection containing a wide and curious range of contraceptive items.