Largest cave system in Africa.

Miles of man-made caves and tunnels are currently used for cultivating mushrooms.

Mined to a depth of 240 meters with a perimeter of about 1.6 km, the largest hand-dug excavation in the world.

The most loyal of little dogs, or a Victorian era publicity stunt?

This African beach is home to thousands of rare mainland penguins that are known for their annoying voice.

This bridge is the first to be made entirely from iron, but designed like it was still made of wood.

Brussels' favorite peeing boy has a sister.

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

An alien church provides much needed silence in the midst of a Finland shopping center.

Former headquarters of the KGB.

Baroque celebration of the end of the Great Plague of Vienna.

The view that inspired the scenes of Dracula's first landing in England.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

In Egypt's expanding metro area, many of the neighbors are dead.

340-foot statue built to honour the Heroes of the Soviet Union.

This lake-bound geographical marker sits at the point where three European countries intersect.

One of the world's most complex timepieces.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

Astonishing rock formations dot the Brimham Moor landscape.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

The "dragon babies" of southeastern Europe.

This magical museum celebrates the life and work of a seminal children's book writer (and occasional spy).

North Korea's massive "hotel of doom."

Beneath Denmark's Højbro bridge, a bronze merman and his seven sons forever mourn for the mother and wife who left them for land.