This striking observation tower shaped like a spinnaker sail is the newest icon in historic Portsmouth.

Want to properly offend a king? Sculpt a giant hill figure in chalk of him riding out of town.

The castle still holds traces of the abandoned Roman fort it was built atop.

An impromptu shrine appeared shortly after beloved "Torchwood" character Ianto Jones was killed off the show.

According to legend, this bell once belonged to a kingdom now lost beneath the waves.

The remains of the great moral philosopher reside in a university in London.

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

The modern birthplace of Irish freedom.

The ship built to ferry passengers and goods to the doomed Titanic is now the last remaining White Star Line vessel.

These engineering masterpieces are a dominant feature of the Belfast skyline.

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.

The true age of this ancient stone circle is unknown, but its stunning vista isn't in question.

The discovery of this Neolithic settlement, which contained a Stone Age "cathedral," threw archaeologists for a loop.

Possibly the oldest of Britain's ancient henges is also one of its most stark.

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

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

360° views of the city plus five floors of optical illusions and hands-on science.

The most loyal of little dogs, or a Victorian era publicity stunt?

Even though some of the buildings date back to the Victorian era, this research institute is still involved in cutting-edge astronomy research.

Bronze plates placed around this Scottish fishing village form a true-scale model of the solar system.

Every St. Andrews student knows to avoid this inscription for fear of a martyr's curse.

This bronze statue was erected to honor a small Scottish town's beloved stray cat.

One of the last remnants of the Bessemer process that revolutionized steel production during the industrial age.