One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Hungarian mummies in beautiful painted coffins.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

Eighty million natural history specimens call this gargantuan museum home.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.

The celebrated eyesore created by starry-eyed sweethearts.

The video game-themed street art first popped up in the French city.

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

Paris' linguistic guide to the international language of, yes, love.

This endearingly discomfited urinating statue commemorates the sneaky pees had by us all.

This irregularly shaped sea fortress has defended not one but three different sovereign states.