A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

This star-shaped military outpost is now simply trying to protect itself from neglect.

The stunning interior of this Gothic church is covered in ornate gold details.

The medieval castle built as headquarters for the Pope's secretive Knights Templar.

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

A small Portuguese cottage formed between boulders in the countryside.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

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

Houses are tucked between, on, and underneath giant boulders.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

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

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

Once an opulent Art Nouveau hotspot, the Constanța Casino is one of Romania's most beautiful abandoned buildings.

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

This massive underground salt mine now holds a sci-fi theme park in its depths.

Moss and stone turn this waterfall into an otherworldly liquid veil.

A magnificent, Disneyesque chateau built for 150 lucky kindergarteners.

Inside the world's largest seed bank, WWII botanists elected to starve to death rather than compromise their collection.

A former military outpost of Ivan the Terrible, the 16th-century church contains some of the rarest examples of Eastern Orthodox mural paintings.

Russian researchers who have been excavating ancient squirrel burrows may have brought a 32,000-year-old plant back to life.

Ukrainian defense contractor's center for studying "pyramid energy."

Home of the future Emperors of Russia.

The "Mystery and Company of Merchant Adventurers" is an Elizabethan-era hangout in Moscow.