Freemasonry is a historic fraternal order that has been shrouded in mystery for centuries, but it turns out, the masons are pretty open to letting you in on a few of their secrets. Untapped Cities Insiders recently got to tour the Masonic Hall and Grand Lodge of Free and Accepted Masons in Chelsea where they learned the history of this organization and were guided through the many intricately decorated lodge rooms by brothers in the order who were more than willing to shed light on the not-so-secret-society.

There are many places around New York City where masonic influence can be seen, but the Masonic Hall on 23rd street serves as the headquarters for the entire state of New York. This two building complex made up of commercial and masonic spaces serves is home to over sixty masonic lodges, or groups who meet there regularly. The Hall was built in 1910 by architect Harry P. Knowles, who was a Master Mason. The meeting rooms underwent a major restoration in the mid-1980s through the 1990s by interior designer Felix Chavez. Though not all of the secrets of the order were revealed to us on our tour, but we did learn many interesting facts and cleared up a few misconceptions. Here are the top 10 secrets of New York City’s Masonic Hall:

1. Freemasons are the Largest Fraternal Order in the World

Though the exact point of origin for Freemasonry is unknown, it is widely believed that it started in the Middle Ages in Europe. According to the Masonic Association of North America, the oldest document that makes reference to Masons is the Regius Poem which was printed around 1390. The first Grand Lodge and official records of organized freemasonry started in London in 1717 and the first lodges in America date back to the 1730s. The Grand Lodge of New York was established in 1782. Over the centuries the order of freemasons has spread globally and now counts an estimated 5 million worldwide members with over 2 million freemasons in the United States alone.