Burial site of a Jewish prophet revered in Iran.

Ancient structures used to make and preserve ice in the deserts of Persia.

Hydraulic systems in an ancient underground Iranian city.

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

This subterranean funicular is one of the world's smallest subways.

As the Dead Sea continues to deplete, massive sinkholes open along its banks.

The ghost town where the villagers refuse to leave.

Cave on extinct volcano, once home to famous mathematician Pythagoras.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Cretean quarry suggests real-life site for ancient Greek myth of the man-eating Minotaur in his labyrinth.

Monasteries on rock pillars, once accessible only by frayed ropes.

1% of Greenland's entire population used to live in this single building, which is now slated for demolition.

Though they've since been renamed, these two streets hint at Dublin's darker days.

An Iron Age fort on the edge of a seaside cliff offers a glimpse into an ancient, mystical world.

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Housing the groundbreaking maps and globes of Gerard Mercator.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

This former Masonic lodge has been transformed into part museum, part bar, all awesome.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

The Devil’s own choice when he needs a drink in Brussels.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

The world's first ice hotel is still one of the most elaborate and beautiful.