A clear example of the process of erosion in action.

One of the best beaches in the entire world.

Prehistoric park filled with the fossils of dozens of extinct species including Australian megafauna.

A sparkling sandstone cliffside that's worth a visit while it still exists.

An opal mining town in the middle of Australia where people live, worship, and shop underground.

Built over an abandoned train yard, this hidden gem is full of winding paths and offers gorgeous views of Sydney Harbour.

A massive stairway that almost wasn't leads to one of Australia's most scenic vistas.

Nature is leading a successful mutiny on this century-old freighter.

This demon atop the Notre-Dame de Paris looks utterly bored.

The celebrated eyesore created by starry-eyed sweethearts.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

France's national museum of scientific and industrial instruments.

One woman's decades-long obsession with the "La Fée Verte."

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

A 90-year-old underground water reservoir offers a more industrial kind of tranquility.