In 1927, a biplane disappeared while attempting to complete the first non-stop transatlantic flight between Paris and New York City. This memorial stands at the last place it was seen.

Immortalized by artists, this church incorporates a medieval lighthouse into its shoreside structure.

An underground city of ancient quarry tunnels hid thousands of Allied soldiers in WWI.

A unique zoological park home to over 30 species of wild cats, both big and small.

A small house sits between two huge rocks, with its back to the sea.

A Franco-era dam flooded (almost) everyone out of this centuries-old Aragonese town.

A Spanish town built into the cliffs.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

Baroque celebration of the end of the Great Plague of Vienna.

Bizarrely-painted church designed by a controversial artist.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Resting in the middle of an Austrian river, this sci-fi "island" lets people cross in neon style.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

An Austrian house of bones filled with hundreds of intricately painted skulls.

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

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

This line of 12 tower mills described in the story of Don Quixote is among the most iconic landscapes in Spain.

Spain's stunning solar energy plant.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

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

This quaint Spanish village agreed to be painted blue as a marketing stunt but found that they preferred it that way.

The world's largest wooden structure.

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