Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

Ancient serpentine sacrifice holder that has stood the test of time.

A fountain standing as a testament to a doomed alliance.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

Turkish adventurer antiques in the heart of the Grand Bazaar.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.

The Titanic sails again in one Scotland man's backyard.

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

Most of Britain's gold reserve was secretly stashed here after the start of World War II.

Twice a year, this Orkney town hosts a rowdy game of medieval mob football.

These murals stand as reminders to the troubled history of this Northern Ireland city.

A museum dedicated to the tragedy of Bloody Sunday.

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

One of the largest lenses of its kind ever created, this former ship beacon has been brought down to Earth.

The last Victorian market in Belfast.

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

The bell that once tolled atop a lost Edinburgh gate now hangs for all to see.

The grand complex of buildings that comprise Liverpool's Exchange Flags includes a vast World War II bunker that has been frozen in time.

This Roman relic was discovered in Scotland by a mudlarking ferryman.

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

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

It was once nicknamed "the most bombed hotel in Europe."

The tower was originally used as a chimney for the waste incinerator of St. John's Precinct and Market.