This obscure walkway links Edinburgh’s Old Town with one of the city's prime vantage points.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Eat the ultimate iteration of Portugal's most beloved pastry.

An exquisite collection of fairytale conveyances that puts most car museums to shame.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

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

This historic streetcar system has been running since the 19th-century.

Elaborate tile work in this railway station tells the story of Portugal.

A hidden three-foot-wide house separates these two regal churches.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

An unusual round church in London with a Templar past.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

A dilapidated dock tells the story of Titanic's missed arrival.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

Elevated freight railway turned wildly successful urban park.

Largest Roman Catholic church in North America.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

A popular European tradition makes its way to the states on one of America's most famous bridges.

A restaurant on Staten Island showcases a different grandmother’s cooking every night.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.