A complicated contraption for telling time by the moon.

Local legend says Isaac Newton built this footbridge without any screws, bolts, or nails.

The Cambridge pub where Francis Crick announced that he and James Watson had discovered the DNA double-helix.

Morocco's largest Jewish cemetery.

Numerous impressive carvings are embedded in the trees lining this street in Marrakech.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

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

Extremely famous in his native country, this Cracovian painter is all but unknown beyond Polish borders.

The Guardian of Tallinn.

A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

Flamboyant architecture from the turn of 20th century.

A stone marker and sculpture in the city of Riga stake a claim for the very first community Christmas tree.

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

The oldest housing complex in Riga is a mini timeline of architectural trends.

This unassuming building produced some of the world's most famous bells.

Legend says these colorful, invasive residents are the descendants of birds released by Jimi Hendrix.

This hospital helped pave the way for treatment that drove down child-mortality rates in 19th and 20th centuries.

This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.

The commemorative stone column conceals a secret laboratory.

An architectural oddity hides in plain sight on this iconic London bridge.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

This beautiful deer park was built so King Charles I and his court could go hunting while escaping a deadly plague outbreak.

Historic church where a number of Shakespeare's actors are buried.

This marine reptile was discovered by one of the 19th century's greatest fossil hunters.