Halkidiki is a three-pronged peninsula just south of Thessaloniki. The area has some of Greece's best beaches, surrounded by forestland and pure nature. The left-most prong, Kassandra, is the place to go when you want to party. It's got great beach clubs that rival those in Mykonos. Sithonia, the middle prong, is more laidback and a great place to soak up the natural beauty while camping. It's got great coves and bays to explore, and way fewer people. The last prong, Athos, is home to a monastic community and can only be visited with preapproval.