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

The world's largest wooden structure.

Giant topiary dog once played a role in a terrorist bomb plot.

A preserved college lock-up that recalls a clubhouse approach to discipline.

It houses the remains of a 17th-century version of the Titanic.

A theatre built to house the rowdy Oxford graduation ceremonies became the stage for a debate about God's existence.

A musical instrument played by the sea.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

The celebrated eyesore created by starry-eyed sweethearts.

A Nesting Doll of Churches.

A Museum of Psychiatry in a still-operating mental institution.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

Macabre astrological automaton clock dating to the late 1400s.

One of the largest underground systems runs under Canada's largest urban center.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A 26-foot shark sculpture—a statement about bombs—set off a municipal battle royale.