Take a tour of one of New York City's most important and exclusive historical buildings

Not just any old tourist can waltz into the Woolworth Building.

Once the tallest building in all of New York City, the Woolworth has been recognized as a historical landmark since 1983.

Completed in 1913, the building was equipped to maintain its own electricity, heat, subway entrance, and barber shop.

With tenants such as Nikola Tesla and the Manhattan Project (the team that helped develop atomic bombs during World War II), the building has been coveted by historians and New Yorkers for decades.

After the building's observation deck closed during World War II, the building was completely closed to tourists until 2013. Even now, access is somewhat limited.

Luckily, Untapped Cities has given a handful of tours inside the building, just to show what it's like after all these years. We joined them for their September tour, which even included an exclusive look at the basemenet.