This ordinary-looking rock may have played an important role in a 16th-century Scottish battle.

A free public golf course hides in plain sight in the heart of Scotland’s capital.

This historic pub has maintained much of its 1906 decor, including a small sequestered room for women, where orders were slipped through a tiny window.

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

An American ghost town hides along a side street in Scotland's capital.

One of Ireland's lesser-known megalithic structures.

This historic timepiece was a popular meeting place for romantic rendezvous in the 1960s.

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

Neon artworks light up this dark Edinburgh tunnel.

Now home to a drinking establishment, this building has a macabre history.

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

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

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

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

A secret garden in a picturesque Edinburgh village has inspired artists for centuries.

The U.K.'s first underground railway line is now a lively thoroughfare for runners and cyclists.

An exquisite Baroque church in Vienna's old town.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

The Habsburgs' royal collections of art and wonders.

This beautiful Brooklyn monument over a crypt memorializes a grim and largely unknown story from the American Revolution.

A bay of elaborate, historic toilets are held in high esteem at this Scottish dock.

Inside this art museum resides one of Glasgow's most famous musical instruments.

These rusting, skeletal structures are monolithic monuments to Glasgow's industrial past

A shiny sculpture celebrating the mighty mollusk.