Art and a pun, all in one.

Ruins of a German Castle on top of a towering stone pillar.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

The world's only museum devoted to the wonders of fluorescence.

Survival capsules find a second life as a unique hotel.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

A historic observatory now an astronomy museum beautifully situated at the moat of the Middle Age city centre.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.

This Netherlands museum holds a gloriously mechanical collection of ornate musical automata.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

Peek through a transparent pyramid and drink in the mountain made of books.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

A Portuguese Jewish cemetery filled with stunning grave monuments that date back to 1614.

A unique collection of gilded age mechanical pianos.

This basement museum explores the art and artistry of fascism.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

A beautifully eclectic mix of architectural styles.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

The attic of a four-century-old canal house hides a clandestine church.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.