A replica of the Liberty Bell rang daily from West Berlin's City Hall throughout the Cold War.

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

Metro station with a claim to rock n' roll fame.

The architect of this fanciful complex called it an "oasis for humanity and nature in a sea of rational houses."

A secret hatch containing two parchments was discovered in this statue over 40 years after its installation.

Stone memorial that's said to predict the death of the pope and the site of the Cadaver Synod.

Remnants of a 4th-century church with vivid medieval frescoes and ancient sarcophagi hide beneath this old basilica.

The mystic whose incorrupt corpse still attracts the faithful.

The final resting place of the poets Shelley and Keats.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

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 hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

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

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

Believed to be the remains of the lost Temple of Minerva, this nymphaeum has been known by its misnomer to this day.

This ancient market is often referred to as the oldest shopping mall in the world.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

A statue representing a lost Roman profession that was vandalized for centuries.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

A forgotten "city of water" underneath the famous Trevi district.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.