Summer is upon us and as we celebrate the long weekend we're looking back at the best celebrity vacations over the years. We'll never forget the time Justin Bieber held Selena Gomez during their romantic getaway, or when Gwyneth Paltrow flashed her grin during a family beach day before she and Chris Martin split. Of course, the celebration wouldn't be complete without the queen of relaxation Kate Moss or the bikini-loving Jennifer Aniston. Whether you have plans to hit the beach or relax at a pool, mark the Fourth by taking a look at our favorite stars in the sun! And for even more sexy celebs, check out our ultimate bikini slideshow.