Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.

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

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

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

Built in the 16th century, the tower is now in ruins.

A once extravagant mansion, now reduced to ruin.

This iconic 1,000-year-old medieval castle is a favorite of the film industry, most notably as the location for Hogwarts in Harry Potter.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

An ancient yew tree and holy well nestle beside a remarkable 13th-century church.

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

An abandoned, desolate train tunnel that was used during World War II.

A collection of historic buildings in central Birmingham blend seamlessly into the cityscape but have an interesting story to tell.

This is the site of the medieval holy well of St. Chad.

In an arboretum with hundreds of memorials to the fallen, this one might be the most poignant.

An 18th century monument regularly tagged with unsettling graffiti referencing a 1940s unsolved murder.

These centuries old gardens have been restored to their 17th century condition.

Some wattle-and-daub, a Moorish mural, a glacial erratic, and a Giant named Gilbert.

This ornate English estates "Prodigy House" still bears the cannonball marks of civil war.

England's foremost purveyor of funeral furniture hasn't changed a bit since the 1960s.

This historic abandoned train station looks like a stop for ghost trains.

This extinct volcano rises above Edinburgh and is special for its panoramic views over the city.

One of Edinburgh's oldest pubs hides a 19th-century skittles alley in the back.

These ancient sunken lanes were naturally tunneled into the soft ground by countless footsteps.

This lesser-known geographic marker was the reference point for all surveys of the continent for 75 years.