The Grand Lodge of New York is located in the Flatiron neighborhood of New York City and it is the headquarters for all Freemasons in the state.

Although the building looks like a normal structure from the outside, inside there are elaborate rooms and lodges that hint at what goes on behind the scenes at this secretive organization.

Insider recently took a tour of the building, getting a glimpse at rooms like the Grand Lodge Room, which can seat 1,000 people for state-wide meetings.

The building is also filled with smaller "lodges" that are themed, like the Gothic Room and the Colonial Room.

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There are six million Freemasons living in the world right now.

With a number that high, it should be easy to find out what exactly a Mason is and what they believe, but the organization has a reputation for keeping tight-lipped about what goes on behind closed doors.

Freemasonry can be traced back to the medieval ages, but there are still lodges all over the world that host meetings. In fact, New York City is home to the Grand Lodge of New York, the headquarters for the state. Incredibly, despite being one of the most secretive organizations in the world, they welcome guests into the building every day for tours.

Insider took one of these tours and saw firsthand where all their meetings take place. Keep reading to find out what it's like inside.