A monument to the grand synagogue that stood in this space before Nazis burned it down.

One of the world's largest amber altarpieces is housed within this reconstructed medieval church.

A masterpiece of Rationalist architecture in the center of Madrid with lizards on it.

Often mistaken as a medieval Gothic monument, this unique cornerstone only dates back to the 1980s.

Despite the name, this ancient piece of crystal may not have been a lens at all.

This small chapel built into rock is the oldest place of worship in Luxembourg.

A monument commemorating the 852 lives lost in the sinking of the MS Estonia.

A non-stop elevator ride in Vienna's city hall.

This free museum is building a collection of books that are banned, censored or burnt around the world.

Hundreds of signs pointing to the birthplaces of current Helsinki residents form stalactites on the ceiling of the cave-like Kamppi metro station.

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

The mirrored section takes the shape of Hebrew characters when viewed from above.

More than 200 eclectic sculptures surround the artist's home.

Automatons that were once removed after one fell from the building.

A massive mammoth bone has been on display inside this church since the 18th century.

The official motto of Luxembourg reminds passersby of the Luxembourgish commitment to their national identity and sovereignty.

This memorial to a murdered empress took 20 years to design, then spent 30 years hidden away in storage.

A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

Dedicated to the outnumbered Finnish forces who pushed back Soviet forces during the conflict.

The concrete skeletons of an abandoned Swedish town hide among the trees.

A tiny village is home to the world's only diner completely devoted to the many varieties of traditional Swedish dumplings.

The first overseas server for Facebook in Sweden's tundra.

Explore the frozen river and take a walk to a nearby island on some of the longest ice roads in Sweden.

The world's first purpose-built indoor shopping mall opened in Sweden in 1955.