Halkidiki occupies the S part of the province of Macedonia, SE of Greece's second city, Thessaloniki (Salonica). 61 mls across and 55 mls from N to S, it extends from the NE mainland into the Aegean Sea in 3 distinctive, finger-shaped peninsulas called, from W to E, Kassandra, Sithonia and (Mt) Athos. Halkidiki has a mixture of agricultural land, especially vineyards, and pine forests; there are some therapeutic springs.
It becomes more hilly to the E, culminating in the 6,670-ft Mount Athos on the E "finger". Its other major geographical point of interest is the Cave of Petrolona, a collection of underground galleries and canyons as well as an important archaeological site where ancient human remains were found. Most of the holiday resorts cluster on the E side of the Kassandra peninsula. Sithonia has far fewer resorts while the Athos peninsula is occupied only by monks living in eyrie-like monasteries built into high cliffs.
No women are allowed to enter here so sightseeing is restricted to coastal cruises for the fairer sex while their privileged male partners may land and visit only with special permits. The area is served by Thessaloniki airport, 10 mls S of the city. There are plenty of Blue Flag beaches with white or golden sand in sheltered bays, some enclosed by high cliffs.