The first and only carousel with a lineup entirely of insects.

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

Hidden inside one of the world's most well-visited zoos is a secret plaque promising eternal life.

Mysterious 500-year-old tapestries depict a unicorn hunt.

One of the earliest bowling lanes in the U.S. doubled as a sewing school during a time when women had little job opportunity.

This fancifully decorated Victorian home in New York’s Hudson Valley is the only known fully domed octagonal residence in the United States.

This once-grand marvel of engineering is now 41 miles of scenic hiking trail.

A waterway covered over after the Industrial Revolution has been unearthed and cleaned up, for the enjoyment of fish and humans alike.

A beautiful, historic location open to the public.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.

An abandoned horticulture institute gloomily presides over rows of derelict and vine-wrought greenhouses.

A haunting contrast of trains that both saved and took the lives of Jewish children in Nazi Germany.

Tiny memorials honor individual victims of the Holocaust.

Dedicated to the European Sinti and Roma peoples murdered during the Holocaust.

At one of Berlin’s oldest churches, visitors can place mosaic tiles to help restore a medieval mural.

From Iggy Pop to David Bowie to Nick Cave, this regal music studio has served some of the all time greats.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A memorial in the Tiergarten is a reminder of the suffering inflicted on homosexuals by the Nazi regime.

After a nearly successful attempt on Hitler's life, the conspirators met their fate in the courtyard of this Berlin building.

The site where a plot to assassinate Hitler was planned—and its conspirators were executed—is now a powerful memorial to the German resistance during World War II.

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