The largest brick bridge in the world.

This historic stone bridge has an entire neighborhood clinging to its sides.

Beloved children's TV characters freckle the German city's streets.

Oberweissbacher Bergbahn - a broad-gauged cable car capable transfering railcars.

"The most colorful grottoes of the world.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

One of the great treasures of Neolithic art lies within this carefully constructed pile of rocks.

If they push on just the right spot, even the weakest person can move this titanic boulder.

An isolated 17th-century chapel on a remarkable site once dedicated to Celtic sun worship.

The oldest Roman lighthouse still in use.

This enormous censer uses a pulley system installed over 400 years ago.

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

Giant topiary dog once played a role in a terrorist bomb plot.

An unusual, funny and fantastic open air museum.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

Eat the ultimate iteration of Portugal's most beloved pastry.

Perhaps the most spectacular grotto along the Algarve coastline.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Of five volcanoes located in the massive Tengger caldera, this cone is the youngest and most active.

This massive complex is made up of hundreds of smaller temples that date back to the ninth century.

Hundreds of Buddhas in a re-discovered Indonesian temple.

The name of this ancient Indonesian temple translates as "Elephant Cave" but it could be more accurately called "The Hellmouth."

A memorial dedicated to the victims of the My Lai Massacre.

Giant pagoda houses the car that drove Thích Quảng Đức to his death by self-immolation.