The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

This is the oldest Roman-made bridge in the city still existing in its original state.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

This unassuming bridge is most likely one of Michelangelo's unfinished masterworks.

This hidden alley near the location of Rome's first theater was the site of a curious miracle.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

A massive marble foot is tucked away in a small alley near the Pantheon.

Plaques on its facade commemorate the Tiber's most destructive deluges.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

A deep mark on the remains of a Roman temple, believed to be left by a legendary warrior.

An 18th-century post box used to alert the church of sick and ailing foreign pilgrims.

An 18th century fountain and two columns are all that remains of Rome's forgotten river harbor.

A large replica of a monumental Roman inscription is located on the side of this museum.

This large, circular tomb is the final resting place of the first emperor of Rome.

Romans decided this 16th-century "talking statue" was so ugly, they named it after a primate.

Inside this building is another country within Rome, a sovereign entity without a physical territory.

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

This charming Latvian lane doubled as Baker Street on the Soviet Union’s version of Sherlock Holmes.

Legend has it that Napoleon Bonaparte fell in love with this Gothic church.

An abandoned masterpiece of Soviet Brutalist architecture.

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

The giant statue and its model solar system honor the native Pole who declared that the Earth revolves around the Sun.

Hundreds of notes give thanks to the patron saint of lost causes.