Science meets wall art to highlight the beauty of famous mathematical equations.

One of the great math minds of the 17th century is underfoot in this 900 year old Dutch church.

A nearly 25-foot concrete sculpture of Sylvette, Picasso's muse.

Underground monastery and fortress.

A fountain filled with golden statues, celebrating the the ancient kingdom of Colchis.

Small church on top of a huge rock column.

These Stalin-era industrial 'death traps' hang lifeless above the city

At this rare mosque in Tbilisi, Sunni and Shia Muslims pray side by side.

Once a forgotten city-wall tower, now the centerpiece of an underground bicycle parking.

A striking memorial to the Jews of Leiden who were murdered during World War II is scattered throughout the city.

This Dutch art piece became a Russian icon.

This historic Dutch newspaper building is covered with media-themed details—and one unrelated oddity.

A folk-art cottage and hotel straight from a Slavic fairy tale.

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

A modern museum dedicated to the fairytales and dictionary work of the Brothers Grimm.

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

Only a few walls remain of the last church the Pilgrims used before they sailed to North America.

The works of poetry's biggest names grace the walls of the city of Leiden, all carefully painted by hand.

The largest 19th century panorama in the world still in-situ.

A storm shelter built for survivors of shipwrecks.

The struggle of a small Dutch island against the sea.

This former hydraulic laboratory is now a woodland dotted with old engineering models.

This medieval castle was painted pink as part of a now-abandoned children's theme park.

A grassy pyramid named after a French battle.