The most metal church of all time was built in record time because of an international, pious pissing contest.

The best-preserved Roman small town in North Africa.

The largest and best-preserved Roman amphitheater in Africa was designed to seat 35,000 people.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A patchwork of ruins from various civilizations in one of the world's oldest continually inhabited cities.

Putrefaction plateaus in Iran, where the dead were sent for decontamination before going to their final resting place.

A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.

The palace of the King of Kings, burned by Alexander the Great.

An outstanding piece of retro Sci-Fi architecture built into a sacred mountain.

A geological oddity topped with a 2,000-year-old pagan temple.

A striking symbol of the Bulgarian capital.

This ancient Silk Road outpost overlooking the Wakhan Valley is miraculously still standing.

Once described as the "Eagle's Nest," this ruined ancient city rests on a remote mountaintop.

This historic black and white monastery is one of Bulgaria's architectural jewels.

The first tunnel to be dug beneath a river, repurposed as an art and museum space.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

Mirrors and glass shards cover every inch of this arrestingly beautiful mosque.

This ancient city—home to nine civilizations—is soon to be buried under 200 feet of water.

Balanced on four stone pillars, this historic tower was the site of a tragic political assassination.

This hunter-gatherer architecture is believed to be the oldest religious complex known.

Mausoleum and Holy Seat of Antiochus I of Commagene.

The largest Neolithic ruins in the world hide a notably clean prehistoric metropolis.