An optical Illusion once believed to be an electrical phenomenon.

The building where Mary, Queen of Scots was said to have bathed in white wine.

The world’s second-largest flood defense barrier has protected London for decades.

Scotland's claim to the prime meridian was laid 200 years prior to the one in Greenwich.

This enormous, elaborate tomb looks oddly out of place next to a suburban Edinburgh bowling club.

A rare and unique example of an 18th-century door latch calls this restaurant home.

A stone-filled garden in the heart of Edinburgh commemorates the father of modern geology.

Small sculpted heads of prominent phrenologists mark the outside of their former headquarters.

Neon artworks light up this dark Edinburgh tunnel.

An ancient healing font dedicated to an 11th-century matriarch was moved to make way for progress.

A discarded umbrella stand from a women's prison is an object of pride at a library that is dedicated to women's culture and achievements.

Memorial to the Titanic engineers that died working to hold back the sea.

An extended zoological collection that doubles as a time capsule.

This statue of a celebrated soldier was removed from Dublin and reinstalled in rural Northumberland.

A dozen cast iron leopards stand guard along the length of Aberdeen's Union Bridge.

This effigy was crafted to annoy a neighbor after a civil dispute over a foul smell.

This rock bore witness to the last pitched battle fought on British soil.

One of the first reinforced-concrete buildings built in the UK, now abandoned.

A series of mysterious metal artwork adorn this harbor walkway.

This 1920's sandstone war memorial was constructed with an unusual drinking trough for horses.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

The barrel-made lookout from Shackleton's final ship is tucked away in the crypt of one of London's oldest churches.

The pretty iron lamp is a reminder of the architecture underneath London's streets.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.