Last night Coach hosted the perfect Summer party — what better way to spend an evening in NYC's Summer heat than out on the High Line at a carnival?! We joined the fun (and even tried our luck at the dunk tank), but between the party games, we were checking out the covetable Coach collection and, of course, our favorite celebrities in their coolest event attire and cute bags from Coach's new Legacy line (dropping in stores and online Aug 1). A night out in the Summer heat calls for easy dressing, just the kind that favorites like Jessica Stam, Kate Mara, and Dianna Agron showed off. This trio's mix of pretty dresses and laid-back separates is proof that keeping it on the casual side doesn't have to mean compromising your style. Need a little refresher course in, well, keeping it fresh for your Summer parties? Click on to see these and the rest of the standouts from last night's carnival — plus a look at all the carnival-themed fun. Also, check out more photos from last night's fun on our Instagram acccount. As always, don't forget to tell us your pick for best dressed in the comments.