Taylor Swift's 'Something Blue' for Wedding Is The Empire State Building

A major detail about Taylor Swift's wedding has been unveiled -- her "something blue" ... and it's none other than the Empire State Building!

On Friday, the ESB's official X account shared a video of the iconic structure lit up blue ... declaring it's "Her something blue." While the account didn't name the "her" they're talking about ... it's easy to connect the dots.

As you know, Taylor and Travis are celebrating their wedding tonight at another iconic NYC spot -- Madison Square Garden -- and welcoming 1,000+ guests.

We broke the news about some of the famous attendees -- Benson Boone, Sombr, and Karlie Kloss -- and, we've spotted several others stepping out in the Big Apple to head to the big party.

You can see some of Taylor's closest pals all dressed up and ready to celebrate her and Travis' love in the above gallery -- we've got pics of Zoë Kravitz, Tay's high school bestie Abigail Anderson Berard, her longtime publicist Tree Paine, and more!

We've also uncovered some details about inside the event space -- we're told there are ceiling-to-floor drapes helping transform the space into a dream venue ... plus a castle and a greenhouse surrounded by trees and beautiful flowers.