Halkidiki's appeal is split between three very different landscapes: long sandy beach resorts on Kassandra, pine-fringed quiet coves on Sithonia, and the closed monastic world of Mount Athos. Inland, the peninsula keeps a handful of unexpected highlights — a major Petralona cave, Aristotle's birthplace at ancient Stagira, and the well-preserved Hellenistic town of Olynthus.