Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

Paris' linguistic guide to the international language of, yes, love.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

This massive library holds what was once the largest book collection in the world.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The largest known Ancient Egyptian obelisk.

This ancient structure is widely thought to be the oldest intact pyramid in the world.

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

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

A marvel of Byzantine engineering under the streets of Istanbul.

You'll find just about anything in this funky Tbilisi flea market.

Despite being tiny and rural this Georgian airport looks like a sci-fi boondoggle.

A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

A small but hugely whimsical theater where marionettes play out the "The Battle of Stalingrad."

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

Unusual building appears to be haphazardly built from randomly piled bricks.

Take respite inside this jaw-dropping church while climbing the volcano where Georgia's Prometheus was once chained.

Fortified homes of highland warriors that are still in use today.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

Underground monastery and fortress.

How this Pine Barrens hill got its name is uncertain, but on a good day the view from the fire tower is crystal clear.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.