The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

Northern Ireland's Brobdingnagian stepping stones.

This huge concrete map of Scotland was built as a thank you gift from a Polish soldier.

A poignant memorial shows the widows and children left heartbroken by the worst fishing disaster in Scottish history.

One of four sister bronze sculptures dedicated to the widows and orphans of an 1881 tragedy.

The one-time stronghold of the noble Douglas family, now home to ghost sightings and nesting birds.

An amazing model of a whale's jaw bone pays homage to the region's seafaring traditions.

A church that bred legends, and served as an inspiration for the Da Vinci Code.

An ancient stone with mysterious origins stands in a residential neighborhood.

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

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

This charming old building's loose connection with the Scottish Reformer is what saved it from demolition after it split apart.

The colorful stairs are made with marble from the world's major quarries.

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

The 20th-century chapel’s intricate woodwork includes amazing details, most notably angels playing bagpipes.

A labyrinthine network of chambers with a storied past hides below Edinburgh's South Bridge.

The Scottish Reformation leader's grave was paved over and is now a parking lot.

A sweet symbol marks the place where torturous executions were once carried out.

Touching this 18th-century Scottish philosopher’s toe allegedly conjures good fortune.

Near the former site of numerous witch burnings, this lavish Edinburgh mainstay pays homage to Scotland's brutal history.

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

This cannonball embedded in the side of an Edinburgh house once served a surprisingly pedestrian purpose.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

A six-ton wedding present for the King of the Scots.