One of the deepest blue holes in the world.

A sanctuary for sickly, stray, or wounded donkeys.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Legend says if this neo-Gothic basilica is ever officially completed, the world will come to an end.

Quito's historic, main square dates back to the 16th century.

The world's tallest aluminum statue is also the world's tallest image of a winged Virgin Mary.

An exhibition devoted to the life (and posthumous taxidermy form) of the last known representative of the Pinta Island Tortoises.

Since the 1700s, this old barrel has acted as a post box that relies on the kindness of travelers.

An Amazonian hotel is the ultimate treehouse and provides stilt based accommodation.

The Ryerss mansion in Burholme Park now houses a community library and a museum filled with a trove of oddities from around the world.

This elaborate towering structure was once famed for its revolutionary height.

A rare view of a preserved Victorian science museum.

This cemetery is dedicated to the people who died fighting for democracy in South Korea.

Millions of numbers carved in glass represent the tattoos forced upon victims.

This massive tea kettle was once a promotional stunt for the Oriental Teashop.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

Narrowest house in Boston.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

The site of Paul Revere's historic two lantern warning.

Two thousand artifacts from around the world collected by one woman who loved to travel.

A gift from Scotland to the United States in memory of the 270 lives lost when Pan Am Flight 103 exploded over Lockerbie due to a terrorist bombing.

An oft-overlooked, magically musical monolith that stands majestically between Arlington Cemetery and the Iwo Jima Memorial.

In what is rumored to be an intentional act of spite, this memorial almost completely obscures the nearby grave of a senior officer.

The romance of early commercial flight still fills this Art Deco destination.