The "Black Arch" guards the entrance to the picturesque Glens of Antrim.

The "father of immunology" used this humble hut to offer the local people some of the world's first free vaccinations.

This ancient oak tree sheltered accused "witches" in the 17th century.

This tiny business claims to be "the smallest pub on the planet."

This innovative steam machine was no doubt the most famous of the pioneer locomotives.

Both church and state get put to the torch in this annual festival in the "Bonfire Capital of the World."

A collection of early 19th century trams set in a reconstructed period village.

A stone obelisk towering over the surrounding countrysides beckons hikers across the rolling moors.

An abandoned tower once used to study the cosmos hides within a thicket of greenery.

A small village in two different countries.

A spectacular disused railway viaduct in a beautiful countryside nature reserve.

A folly built to satisfy a gentleman's bet that he could drive his horses through the eye of a needle.

These remarkable cascades are the jewels of Upper Tees.

Victorian-era Londoners really wanted to believe this 17th-century cistern was actually an ancient artifact.

Forgotten jail cells beneath this Scottish town hall are now used for delightfully artful storage.

This tiny train shuttles passengers to one of Northern Ireland's most spectacular sights.

It is said a heartbroken man visited the gap every day to stare blankly out at the sea.

This amazing trail among the many waterfalls around Ingleton has been enchanting visitors since 1885.

This 17th-century pub once had a hole in its wall so the neighboring blacksmith could easily access beer.

At just 25 inches at its narrowest point, it's one of the tightest streets in the world.

One of the few surviving street funiculars in the world.

Inspired by a dream, a hermit carved out a home in this sandstone bank to live a life of contemplation and prayer.

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

A stretch of land where the sour-sweet vegetable is cloaked in darkness and grows so fast you can hear it crack, squeak, and pop.