The ancient necropolis houses the immense rock-cut tombs of four Persian kings.

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

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

A 17th-century mosque that was used for war more than worship.

Space-age minarets towering over Islamabad.

Built over an abandoned train yard, this hidden gem is full of winding paths and offers gorgeous views of Sydney Harbour.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A small, but award-winning beach known for its literally spotless reputation.

The world's second-tallest flagpole stands proud despite dropping rank.

This dark, damp, perilous tunnel is the only passage from north to south Tajikistan.

Huge stairway leads to this massive gallery.

Destruction from Armenia's 1988 earthquake inspired an artist's sculptures of scrap metal.

This Armenian monastery was carved out of cliffs and named after the spear used to stab Jesus.

A glittering South Asian anomaly in a wealthy Los Angeles suburb.

One of the world's largest shopping malls covers an area of 15 million square feet—and it's still set to grow.

A 1,500-year-old, 3-story subterranean city where ancient Persians took refuge in times of war.

Long before air conditioning, Persian architects found an ingenious way to cool off.

The fire inside this temple has burned for more than 1,500 years.

This trio of Australian rock spires may have inspired aboriginal legend or just modern tourism.

A massive stairway that almost wasn't leads to one of Australia's most scenic vistas.

This commanding mausoleum holds the remains of Muhammad Ali Jinnah, the founder of Pakistan.

A shrine in Karachi is home to around 100 crocodiles that are regarded as sacred.