The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

The most accurate timepiece in the world.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

Head past the aisles of tropical fruit and imported candy at this bodega to discover a hidden, weekends-only taco stand.

Nine nice parcels of land along a flight path offer a quiet respite... until a plane soars overhead.

The first Catholic church in Singapore is a Neo-Gothic colossus with a rich architectural history.

This 45-story tall abandoned skyscraper is the third tallest building in New Orleans and Lousiana.

This 15-foot tall obelisk commemorating the Philadelphia-Baltimore railroad connection sat neglected for over a century.

One of Kyoto's oldest food establishments has supplied soba noodles to temple priests and the Imperial Palace.

This subterranean oyster house has been the pearl of Grand Central Station since 1913.

The spot where Oxford garnered its name was also home to a medieval philosopher and includes a house covered in statues.

Inside this curiosity shop, visitors can peruse the clown collection or purchase a molar from the mouth of Bigfoot.

These tiny pine-covered islands have inspired art and poetry for centuries.

A spectacular remnant of an Adler and Sullivan masterpiece that was destroyed in 1972.

This 14th-century temple is also known as the "Temple of the Golden Pavilion" for its gorgeous gilded reliquary hall.

This fountain was once heralded as the largest in the world.

This hidden oasis features a stunning view of the Hudson River and the Palisades from a castle-like museum.

Occupied for six centuries by Franciscan Order nuns, this monastery is an amazing ode to Catalán Gothic architecture.

Once the main gateway to Tokyo, sneaking through this checkpoint was a capital offense in feudal times.

This former INS center is now home to a thriving community of artists, from performers to painters to architects.

This statue once earned the distinction as one of the "Three Major Disappointments of the World."

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.