The final resting place of the poets Shelley and Keats.

This portrait of Philip V is always hung upside down, in a protest three centuries in the making.

This amended headstone marks the grave of a participant in one of the most successful military deceptions of all time.

A breathtaking and biodiverse wilderness in the mountain setting of Ernest Hemingway's "For Whom the Bell Tolls."

The oldest Roman lighthouse still in use.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Village situated on a narrow volcanic escarpment.

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

Since ancient times these picturesque springs have been providing bathers with healing waters.

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

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Nine bronze hands protruding from a wall honor the student uprising that led to the fall of Czechoslovakia's Communist government.

A controversial artwork draws attention to the dark history of Prague's "Suicide Bridge."

The deepest sinkhole in Central Europe comes with a grisly tale and an unusual nickname: “The Stepmother Abyss.”

The world's greatest slide descends 18 stories from this looping mountaintop viewing platform.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

This artificial cave looks like something out of a fairytale.

Macabre astrological automaton clock dating to the late 1400s.

This formerly-prosperous Silesian mining town was completely demolished in the late 1960s and early 1970s as an attempt to cover up a secret Soviet uranium mine.

A stone in Wolin, Poland, marks the possible location of a legendary Viking fortress.

The giant statue and its model solar system honor the native Pole who declared that the Earth revolves around the Sun.

Poland's oldest salt mine has nearly everything one needs to live underground forever.

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

An underground city of salt.