This 15th-century cave complex is one of the very few monasteries to stay open throughout World War II and the Soviet regime.

An ever-growing literary collection housed in the apartment where the Russian author penned his final novel.

Stunning examples of Russia's 18th-century wooden architecture.

A model village fit for an emperor.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

Gargantuan home of Russian science.

Stalinist skyscraper built with help of cryotechnology.

One of the world's tallest statues is also one of its most hated.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

Moscow's other, lesser known kremlin is a fairytale-like cultural complex modeled after Old Russia.

The oldest operating Mississippi River–style steamboat still navigates the Ohio River.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

This striking art museum holds an amazing series of curiosity cabinets.

The world's largest outdoor organ is played weekly by one of just two civic organists in the U.S.

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

San Diego's most historic and haunted home.

A monument celebrating the idea of reaching inaccessible places.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

Location of a reliquary containing bone fragments of 18 saints.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.