A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

135 bronze medallions mark a French meridian line which once rivaled the hotshot Greenwich timeline.

Skeletons, medical artifacts, and other obscure and precious treasures all displayed in a wooden pharmacist's cabinet.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

Indents in the pavement are all that remain from a grisly death machine in Paris.

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

This enormous 32-foot painting depicts Poland's greatest medieval battle in glorious detail.

These 18th-century paintings of Warsaw were used to reconstruct the city after World War II.

While this monument tile is shrouded in mystery it also marks the end of the longest ever human chain.

The largest coin pyramid in the world is a carefully balanced stack of over 1,000,000 pieces.

A series of concentric circles represented a bold new experiment in socialist urban planning, and it notoriously difficult to get around.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

A black cat protests the City Guild in Riga's Old Town.

Described as one of the Baltic region’s most daring and original construction projects.

The oldest funicular in Lithuania has been climbing this steep hill since 1931.

A Kyiv-based repository for all manners of discarded curiosities.

This former KGB building is now a museum memorializing the people who suffered during the Soviet regime.

Plaques celebrating Lithuanian writers freckle a wall of this picture-perfect path.

These traffic lights celebrate the 100 year anniversary of the women's suffrage movement in Lithuania.

The Frank Zappa fan club erected this monument to their prog-rock hero to mark a new era of post-Soviet Lithuania.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

An existential riddle in the world's largest ancient castle.

A collection of anatomical samples from one of the first anthropologists to suggest that humans reached North America by crossing the Bering Strait.