One of Europe's oldest yew trees has lived more than 2,000 years.

An Antoni Gaudí masterpiece in Astorga.

This "grandfather" eucalyptus is one of the tallest trees in Europe.

Giant granite sculptures representing family on the northern coast of Spain.

The oldest Roman lighthouse still in use.

This enchanting natural park is a magical example of a temperate rainforest in Europe.

Seaside ruins of a settlement that date back to the first century B.C.

A 12th century church completely covered in shells.

Thanks to an acoustic anomaly, this unassuming stone bench has heard one hundred years of secrets.

The mysterious remains of a martyred teenage saint are venerated inside a small country chapel.

Remarkably intact Roman stone fortifications have encircled this Spanish city for centuries.

Giant disc-shaped gate took 20 men to close off this city in Madagascar.

See hundreds of herons and egrets in the heart of the city in this dreamy hidden park.

Fabulous formations, weird and wonderful wildlife.

The centuries-old trees lining both sides of this dirt road may become Madagascar's first natural monument.

The ornate miniature mansions were built for Istanbul's feathered residents.

This ancient subterranean megalopolis is known for the hot oil traps that were installed above each of its entrances.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

Naturally protected city carved from a rock face.

The largest Neolithic ruins in the world hide a notably clean prehistoric metropolis.

The best-preserved ancient theater in the world.

One man's swirling six-acre monument of stone.

This once luxurious Catskills resort is now a haunting ruin.

Locals purchased this abandoned quarry in order to make sure it continues to be overgrown.