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

A small plaque highlights the damage caused by German air raids during World War II.

This massive monument has been telling the time for 150 years—at a slight angle.

Belfast's namesake river still winds below the city center, hidden from sight.

A palatial former bank building now houses what may be the poshest art venue (and former Tesco) in Belfast.

A giant sculpture of the legendary "Salmon of Knowledge" celebrates the return of fish to Belfast's River Lagan.

The only monument to name all of the passengers and crew who died on the RMS Titanic.

For part of the year, this innovative greenhouse is painted white to keep the plants from getting scorched.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

Three stone bridges straddling the River Gowy form part of the medieval road from London to Holyhead—despite a common nickname, they're not Roman.

On a site with a long military history, a 1980s shelter.

Each year a new straw behemoth is born.

A long, winding trek rewards you with a gorge so captivating it inspired a painting in the Tate.

Harry Potter once visited this massive limestone cliff, which was carved by an ancient glacial river.

Great Britain's only hat-making museum.

The house in the middle of the motorway.

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

A succession of eerily contemplative iron figures lead from a Scottish museum to the sea.

This 16th-century house tells the city's history through old artifacts and quirky tales.

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

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

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

The highest peak in Wales is said to be the final resting place of a giant killed by King Arthur.

The final resting place of soldiers' loyal canine companions.