Doris Duke's lasting collection of Islamic Art, hidden in a Hawaiian paradise.

A Hawaiian stairway to heaven—that you can't climb.

Hidden behind a YMCA stands the remains of a ceremonial site that dates back hundreds of years, whose ground is still considered sacred to many Hawaiians.

A 1940's shrine dedicated to drowned fishermen on the outskirts of Honolulu.

Climbing this abandoned railway leads to breathtaking vistas of O‘ahu.

A unique set of caves that spits waves back out into the ocean.

The air force base preserves its scars from the Japanese attack on Pearl Harbor.

A unique collection of Western and Japanese-style graves.

A glass display case holds the document that ended the Second World War—which one person signed on the wrong line.

This coastal cavern is associated with the Hawaiian god of creation.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

Hiding behind a grocery store is a spectacular cavern carved as part of an old limestone quarry.

The oldest continuously inhabited street in America.

The only intersection in America where the buildings on all four corners were built pre-Revolutionary War.

A unique work of art that was created without permission.

A journey to a hand-crafted island involves a trip across this lattice bridge.

A nearly 100-year-old dining car in upstate New York embodies the golden age of roadside dining.

The life of one of FDR's possible mistresses is preserved in her palatial Hudson Valley mansion.

What was once a trend-setting, phrase-coining icon of architectural splendor is now a rotting, forgotten hulk.

"A hideous albatross in the Hudson River Valley."

This mouldering abandoned mental hospital was once a center for progressive healing.

This once-private estate is now a dreamy, meditative garden that's open to the public.

The largest known open fault in the United States is basically a giant natural refrigerator.

The largest Buddha statue in the Western Hemisphere is just 50 miles north of NYC.