Amid skyscrapers and traffic exists this unique aquatic ecosystem.

A celebration of capitalism in Midtown.

Try not to get slimed in Tribeca.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

The "Bridge Over the Atlantic" lets you cross the waterway in mere seconds.

A private home envelops the ruins of this 13th-century priory.

Looking strangely like Rome's Colosseum, this unfinished tower has dominated the skyline for over 100 years.

An eerie collection of the surviving structures from a past celebration of the future.

A monument to one of the greatest matadors of all time.

Spain's largest bullring offers a unique glimpse at architecture and history.

The world's largest wooden structure.

Drink the 'Blood of Christ' in this Roman Catholic fever dream.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Legend says a witch conjured the world's third largest whirlpool to protect Scotland from a nasty pirate.

The artwork is tucked within a cave on a tiny Scottish island only accessible at low tide.

Near this coastal cave stands a small memorial to the hermit who made it his home for three decades.

Beneath this headstone lie the severed body parts of three individuals who were caught up in a bloody period of Scottish history.

Legend says this cave housed a 16th-century cannibal and his family of 48.

A cottage built at the birthplace of Alexander Selkirk, a sailor who inspired the novel 'Robinson Crusoe.'

A square stone tomb marks the spot where six men were killed while holding a service in Caldoris Wood.

The carved medieval stones stand near the ruined abbey's parking lot.

Originally intended as a temporary installation, this sculpture is now a permanent part of a stunning Scottish beach.

Described by William Wordsworth as a "World of Wonder."