The stately remains of Llywelyn the Great's mighty fortress.

This well-preserved Cistercian Abbey in a romantic pastoral setting has inspired artists like the poet Wordsworth.

In the midst of a living monument to Soviet social engineering, Polish Catholics built this church by hand.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

The silly symbol for an underground protest group is now scattered around the city.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

An enormous playhouse designed to look like 21 stacked Lego bricks, with another 25 million colorful Legos inside.

A model memorial to the original Odin Tower, the second highest tower in Europe before it was sabotaged by Danish Nazis.

Atop this former dutch railway office sits an interstellar work of art.

A spitting ode to a German serial killer.

A little-known cafe in an old copper bridge tower with 360-degree views of the harbor.

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

This sublime architectural marvel is a rare example of an expressionist church.

This colorful artistic feature atop a Danish art gallery allows visitors to stroll through a rainbow.

This century-old cinema house has a marquee that has been hand painted by a single man for over 25 years.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

A stairway to heaven, or to nowhere at all.

These 12th-century catacombs carved into a mountainside were a place of mysticism and Christian hermitages.

Amidst medieval and baroque buildings, five human-sized gherkins stand tall.

Ugly 18th-century dwarf statues living in a perfectly landscaped Austrian garden.

New Zealand's only running funicular railway.

A New Zealand communications tower stands as the tallest structure in the Southern Hemisphere.