A sweet symbol marks the place where torturous executions were once carried out.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

360° views of the city plus five floors of optical illusions and hands-on science.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

Hundreds of hidden passageways weave through the old quarters of Lyon.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

France's most famous cemetery, with some of its most curious tombs.

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

There has been an astronomical clock on this spot since the 14th century.

In the summer, the area around this sculpture transforms into a vibrant concert venue.

This 13th century Gothic brick castle is the largest in the world by surface area.

On this Polish road, an optical illusion makes cars seem to roll uphill.

While the U.S. and Soviet Union were engaged in a space race, Poland built a UFO on the ground.

Relive a Polish uprising via an enormous, century-old cyclorama.

In the center of Wrocław's old meat market stands a somber tribute to the city's livestock.

This fairytale medieval church in Poland originally spent centuries in Norway.

A 90-ton, gravity-defiant steam locomotive shoots for the skies in this bizarrely beautiful public artwork.

The Polish capital has had a deep connection to its guardian mermaid for almost a millennium now.

Deep in a Polish forest, this collection of Iron Age megaliths still holds onto many of its ancient secrets.

A collection of old neon signs from all over Poland line a secluded courtyard.

A striking public sculpture representing the period of martial law in Communist Poland.

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

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