Two stone columns flank the grand Venice square, but there were supposed to be three.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Go inside to really appreciate this 500-year-old technological masterpiece.

As can be expected from a centuries-old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

The roof of this ancient mausoleum is made from a single Istrian stone weighing a massive 230 tons.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

Anonymously sculpted and donated, these sculptures made from poetry books and pages are sprinkled around the city.

Touching this 18th-century Scottish philosopher’s toe allegedly conjures good fortune.

The most loyal of little dogs, or a Victorian era publicity stunt?

The final resting place of soldiers' loyal canine companions.

An impromptu shrine appeared shortly after beloved "Torchwood" character Ianto Jones was killed off the show.

The taxidermied remains of a once-great parrot.

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

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

Eighty million natural history specimens call this gargantuan museum home.

Relics of Australia's convict past, and a modern scene of unimaginable horror.

This extraordinary geological oddity resembles human-made pavement.

Bronze statues honor the brave explorers who passed through this Antarctic gateway.

The abandoned remains of a once popular zoo, and the grave of the last known Tasmanian Tiger.

This controversial museum includes such detested exhibits as a chocolate suicide bomber and fecal-smelling digestion machine.

More than 5,000 artifacts donated by the people of the city, plus a room entirely devoted to the band U2.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.