A striking public sculpture representing the period of martial law in Communist Poland.

A collection of old neon signs from all over Poland line a secluded courtyard.

This hidden collection of everyday objects illustrates life within communist Poland.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

This man-made mound monument was built out of soil from all across the Polish empire.

A program of Communist glamour in post-Stalin Poland is preserved in this colorful museum.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

Once called the "Polish Gold Coast" it is an icon of the neighborhood that bears its same name.

A haunting statue called "Eternal Silence" has quite the reputation among visitors with active imaginations.

An enormous park-like oasis, full of famous Chicagoans' graves.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

The "Seinfeld" diner.

Read a book next to a Midtown waterfall.

Elevated freight railway turned wildly successful urban park.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

A crumbling hospital from the 1850s on Roosevelt Island.