A unique Soviet mosaic preserved on the facade of a shoe factory in Lviv.

A century-old church is now a space museum with a treasure trove of Soviet space items.

One of the largest remaining ancient burial mounds of the 10th century.

This museum explores the tumultuous history of Lviv under Nazi and Soviet occupation.

This hidden fortress has been coined the "City of Ghosts."

This underground transport hub doubles as an art gallery.

This Ukranian fortress is one of the best-preserved medieval castles in Europe.

This hill is known for its connection to the occult in Slavic tradition.

Welcome to the world's only museum dedicated to the Ukranian Easter egg.

The deepest metro station in the world.

This derelict superstructure was a very important warning system for the Soviet military.

One of the largest museums in Ukraine remembers the story of the German-Soviet War in iconic, brutalist style.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

Historical figures from New York City's Catholic community reside in Midtown.

This lavish room at NYC's French Embassy is a rare relic from the end of the Gilded Age.

The highest point on the island known for buildings that touch the sky.

This Dutch Colonial home is the oldest remaining farmhouse in Manhattan.

Where now stands a 42-story condominium tower of marble, glass and steel was once the central market of New York’s slave trade.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

Built hundreds of years ago this downtown iron barrier once protected a much despised king.

This abandoned caretaker's apartment is one of 13 left in the New York Public Library system.

Salute the leader of the proletariat.

The site of the deadly Triangle Shirtwaist Factory Fire.

America's oldest Eastern European synagogue provided the immigrants of crowded Lower East Side tenements a space of sanctuary.