Halkidiki is a large peninsula surrounded by the Aegean Sea and is linked to the Macedonian backbone through the area of Thessaloniki. In the southern part of Halkidiki, three characteristic elongated peninsulas are formed which give the area its characteristic shape. From west to east are the peninsula of Kassandra, the peninsula of Sithonia and the peninsula of Athos. The Halkidiki peninsula is administratively divided into the prefecture of Halkidiki and the autonomous monastic state of Mount Athos.
The climate in Halkidiki presents a transition from a Mediterranean coastline to the lowlands, to a terrestrial Mediterranean on the highest areas and a wet continental in the highlands. The Mediterranean climate of coastal areas is characterized by mild winters and cool summers. The climate of the lowlands contributes to the absence of frost or excessively high temperatures.