The bluer than blue waters in these natural Israeli caves are reached via the world's steepest cable car.

Gladiators battle and chariots race daily in the ruins of a once-great Roman city.

The most gigantic, swoony, intimidating trio of fingers in all of antiquity.

This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

These numerous Israeli caves were dug out over hundreds years for reasons ranging from hideouts to burial sites.

The remains of this ancient fortress atop a manmade hill look as though they were built into a volcano.

This nightmarish children's plaything was left grotesque to help kids conquer their fear.

An ancient tunnel in Jerusalem built to redirect water in the event of a siege is one of history’s great architectural innovations.

Descend 2,030 years into the past in an ancient tunnel built to support Jerusalem's most famous wall.

A "miracle" that seems to produce more holy fistfights than holy revelations.

The home of the Dead Sea Scrolls is an abstract modernist dream.

Through a collection of modern bric-a-brac this museum tells the story of the Jewish people from Biblical times to today.

Obscure Freemasons still live in D.C.’s largest private residence.

Hidden in the shadow of a rocky fortress is one concubine’s long-forgotten legacy.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

Dead weights honor the dead of Portugal's fishing industry.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

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

The world's oldest bookshop still in operation.

Bali's remote "gateway to heaven" is one of the most sacred places on the island.

Europe's largest collection of matchbox designs is a fascinating exploration of the cultural history of the world.

The ancient water tanks remain some of the ruined city’s most beautiful architecture.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.