The Empire State Building is one of the most iconic skyscrapers in New York City, a tourist stop for 3 to 4+ million visitors a year. But as we’ve shown here at Untapped Cities, even tourist destinations like Grand Central Terminal and the Metropolitan Museum of Art, have their secrets. Here, we recount 10 secrets (and fun facts) of the Empire State Building.

1. There’s a Decommissioned 103rd Floor Observation Deck

Moses Gates, author of Hidden Cities, made it part of his urban exploration mission to access and raise awareness on public observation decks that have been closed to the public or turned into private spaces. The 86th floor and 102nd floor observation decks are accessible–albeit with increasing ticket prices, but one could only be accessed through the building management or by breaking in, as Gates describes in his book until it was turned into a VIP lounge. A 2012 Huffington Post article, shows that there is a door from the 102nd, a level that reopened in 2005, that leads upstairs.

What’s fun though is that Gates expected to be most impressed by the views but didn’t expect “a history lesson on the Revolution War.” As he describes, there were 16 signs (one already missing on his visit a bunch of years back) pinpointing geographically major moments in the Revolutionary War, like the Battle of Brooklyn. The signs were put up to commemorate the bicentennial of the war in 1976 “and that in 1977 the building was landmarked with the signs still up.”