Northern Ireland's Brobdingnagian stepping stones.

This single room has survived the centuries with almost no deterioration.

A hugely vast Irish landscape of barren rock that stretches for miles.

The ancient tomb acts as a calendar that keeps perfect time.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

These mysterious ancient stone spheres were created by a civilization lost to time and are now mostly lawn ornaments.

This Costa Rican topiary park is a surreal garden of unearthly delights.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The celebrated eyesore created by starry-eyed sweethearts.

The final resting place of the great navigator, or maybe his brother.

The world's largest wooden structure.

Living towers made of people that are now recognized by UNESCO.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This chapel on a cliff is renowned for its healing powers and was founded on the site of a supposed divine intervention.

The bat-covered home of one of the world's most popular brands of rum is located on a tropical Art Deco campus.

The longest navigable underground river in the United States is home to countless blind and albino animals.

The LSU mascot lived on the college campus in one of the most impressive tiger habitats in the country.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.