This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.

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

A series of abstract, silly sculptures represent the works of a great modern classical composer.

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

Immortalized by artists, this church incorporates a medieval lighthouse into its shoreside structure.

The Avenue of Mausolea is a series of grand palatial tombs.

Light still pours into the ruins of this ancient Islamic observatory.

The wartime boat shelter now doubles as an underground concert hall where musicians play on rafts along the waterway.

This collection of lakeside pagodas and temples are flanked by giant lions, tigers, and dragons as well as their welcoming maws.

This Taiwanese promontory is covered in otherworldly hoodoo formations.

A rare pod of derelict midcentury Futuro and Venturo houses lines a semi-abandoned beachfront resort outside Taipei.

Enormous pendulum helps keep Taiwan's tallest building from swaying.

Taiwan's last Chinese character letterpress preserves the dying art of Chinese character mold making.

An imperial art museum offers edible versions of its most treasured displays in an on-site fine-dining restaurant.

A little sculpture with a large wardrobe.

Mysterious craters may have been home to an ancient cult.

A spectacular Petrine Baroque summer palace commissioned for Catherine I by Peter the Great.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

A former imperial sea-fortress and Soviet prison.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

The ruins of a military-industrial complex now host concerts and more.

In the hinterlands of Serbia's capital, a giant reflective mushroom houses an aeronautical history of the former Yugoslav republic.

This dazzling Art Nouveau mansion is now home to the Modern Art Gallery Subotica.

Religious perseverance and cultural coexistence manifest in an architectural gem that multiple wars couldn't topple.