There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

Tucked inside a South Bank bar is an epic expressionist chronicle of the 20th century.

This Viking gravestone carved in a rare runic style was dug up from a London churchyard.

These morbid carvings remind churchgoers of the inevitability of death.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

Never actually a tree at all, this spot was the site of London's public hangings for nearly 600 years.

The remains of an ancient Roman teenager are memorialized at the base of a modern London landmark.

Public access to clean drinking water was an instant hit among the masses.

A clock designed to run with perfect accuracy for 10,000 years.

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

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

This impressive Boston holy house is the American mecca for Christian scientists.

The site where Charles Dickens gave his first public reading of "A Christmas Carol" in the US.

Ralph Waldo Emerson spent two years living here decades before it became a Frederick Law Olmsted-designed park.

Since 1947, this living history museum has been providing an immersive look at life in Plymouth Colony.

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.

The first memorial dedicated solely to the Black troops who fought for the Union.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

Perhaps the most scandalous statue of America's first president.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."