Gabriela Novogratz, daughter of crypto investment tycoon Michael Novogratz (read: $$$$$$), held the biggest bash out East this weekend. Maybe, and mind we say this in our professional opinion, even the biggest bash of the summer!

An open field in Amagansett, most likely part of the Novogratz estate, was transformed into a full on mermaid carnival experience. 

We're talking food stalls, under-the-sea stilt walkers and mermaid entertainers peppered throughout the grounds, and plenty of Instagrammable moments. After all, there was a very Insta-famous crowd in attendance - with guests like Charlotte Bickley, Samantha Cohen, Sophia Cohen, Steven Sachs and more embracing the mermaid theme with colorful, shimmery, crown-topped ensembles.

Now if there's anything you should have learned from My Super Sweet Sixteen, it's that no over-the-top soirée is complete without a surprise performance. And well, let's just say that Gabriela more than outdid herself here. 

Fresh off her set at Lollapalooza, Miley Cyrus hopped off a private plane at East Hampton airport to take this kitschy little backyard stage by storm in a shiny red leotard. Like, talk about a party in the USA, no?

Click through for scenes from the all around epic evening, including Miley doing her thing!

[Photos via @Sophiacohen]