The ancient necropolis houses the immense rock-cut tombs of four Persian kings.

A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.

A former military outpost of Ivan the Terrible, the 16th-century church contains some of the rarest examples of Eastern Orthodox mural paintings.

One of the world's tallest statues is also one of its most hated.

A sculpture park of the tossed aside relics of the USSR, from Stalin to a massive Soviet emblem.

It took over half a century but a Russian monument to a famous and tragic space pup finally stands in Moscow.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

The embalmed remains of the communist leader lie within a custom crystal coffin.

An exceptional assortment of fossils recovered from private collections.

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

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

At 929 pounds and 26 feet tall, this stainless steel fork can only be used by the likes of King Kong.

This Canadian hunting lodge is a long way from home.

This memorial, built by fascist dictator General Franco in 1960, has been repurposed by the people of Catalonia.

Barça football fans might see the insignia hidden in a church window as a divine sign.

A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.