Looking strangely like Rome's Colosseum, this unfinished tower has dominated the skyline for over 100 years.

This eclectic sanctuary is a hodgepodge of various architectural styles, all crammed into one building.

A long-abandoned relic of World War II.

Nestled amid the peaks and lochs of the Scottish Highlands, this inn and pub has played host to outlaws and ghosts.

Overlooking a Scottish loch, this beautifully crumbling castle once inspired a poem by William Wordsworth.

Near the former site of numerous witch burnings, this lavish Edinburgh mainstay pays homage to Scotland's brutal history.

The site of the earliest colonial settlement in the Bahamas started as a place of religious refuge.

This isthmus in the Bahamas narrowly separates the roiling Atlantic from the cool Bight of Eleuthera.

This staircase in a lush tropical grotto was built by enslaved laborers and renamed to honor Queen Victoria's role in ending slavery in the British Empire.

These two giant boulders mysteriously perched on a 60-foot cliff may have been slung up there by a raging tsunami.

A tiny Greek Orthodox church from the Ottoman era hides on a busy city street.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

The ornate structure is part of a building boasting more marble than the Vatican.

A familiar otherworldly creature guards this 12th-century Scottish abbey.

The strange behavior of a tween led to allegations of witchcraft and a curse being placed on anybody within earshot.

One of Scotland's most important modern structures, it just made the '100 Most Endangered Sites' list.

This volcanic plug boasts the longest recorded history of any Scottish stronghold.

This ethereal, rainforest-like gorge is home to waterfalls, quaint bridges, and fairy folk.

Climb this overlooked gem's spiral staircase and you'll be rewarded with spectacular views of Glasgow.

Largest lake in Great Britain measured by surface area.

This castle was established by the 4th Duke of Montrose and is connected to the Buchanan Clan.