A 19th-century cabin built into a hollowed-out Sequoia tree.

Four hundred granite steps were built into this massive rock by the National Park Service.

The legendary building that needed ghostly approval before being built.

Crypt mausoleum in cathedral's basement contains relics of third century Roman martyr, Saint Vibiana.

This hidden fire lookout offers spectacular views of Sequoia National Park.

The second-largest giant sequoia in the world.

The last remnant of a tree that helped prove to the world that sequoias are real—and they’re spectacular.

This massive statue of John Muir on the side of a California highway was carved from a redwood tree.

Quite simply the largest tree in the world (by volume).

This giant sculpture made of trash is a critique of society's wastefulness.

This historic streetcar system has been running since the 19th-century.

A hidden three-foot-wide house separates these two regal churches.

The original version of Porto's most famous sandwich is just as good here as it was a century ago.

The Lone Star plaque hangs in a bombed-out bunker in Normandy to honor a Texan colonel's heroic actions on D-Day.

The site of a legendary battle immortalized in medieval literature.

An Antoni Gaudí masterpiece in Astorga.

This former power station is now a museum dedicated to the region's coal-producing history.

An accidental trick of light casts the perfect shadow of a pilgrim of the Camino de Santiago against the cathedral wall.

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

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

Elaborate tile work in this railway station tells the story of Portugal.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

For more than half a millennia, this automaton has rung an hourly bell.

A natural history wunderkammer in the middle of the desert.