For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

The little-known second castle that William the Conqueror built in York.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

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

A rare set of strings by famed instrument maker Antonio Stradivarius is on display in the Royal Palace.

One of the shortest streets in York has an especially odd name.

A whale rib was used to advertise the store by the arch that offered exotic goods from far away.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

Created by four famous men (Henry Hobson Richardson, Frederick Law Olmsted, Calvert Vaux and Thomas Story Kirkbride), the beautifully designed Buffalo State Asylum was resurrected as a hotel and art center...but still boasts a ghost story or two!

This tiny church near Sleepy Hollow contains Henri Matisse's last work, a rose window, and nine windows by Marc Chagall.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

Discovered by cows, these upstate New York show caves are presented with a healthy dose of psychedelic folk art.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

A century-old tradition has culminated in a small but singular collection of feline effigies.

The first pet cemetery in the United States.

The world's largest wooden structure.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.