A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

A slightly creepy gallery of plaster cast models in the same museum as Michelangelo's David.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

A grandiose octagonal home crowned by a large dome stands out among the antebellum mansions.

An eerie and beautiful group of columns mark the site of a grand mansion lost to time and fire.

This long-distance walking route follows the Prime Meridian line as it passes through England.

The rogue roots are gradually consuming some of the historic marble grave markers.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

The walls of the iconic dome are hollow and have a secret stairway.

Hear the quietest sound from across the dome.

One of Europe's oldest libraries.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

A statue marks the exact spot where The Boy Who Never Grows Up made his first literary appearance.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

Nature took her revenge on the "Wickedest City in the World."

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

Legends surround an ancient tree trunk riddled with nails for good luck.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A museum and shop on Bourbon Street located in the former home of the second Voodoo Queen of New Orleans.