By plane: You can reach Chalkidiki by plane using the airport "Macedonia" Thessaloniki. Then you can take a Bus, a Taxi or rent a car.
By Bus: You can take the bus (KTEL) to arrive in Halkidiki directly.
By Boat: The nearest port is in Thessaloniki, or if you come from the East Sea to use the port of Kavala.
Chalkidiki is a region of Macedonia and geographically constitutes the ending of Central Macedonia in Aegean sea which penetrates deeply into it, forming three oblong peninsulas that give the area its characteristic shape ( "legs of Chalkidiki").

Halkidiki is a large peninsula, that is washed by Aigaiopelagos only N. NW. It is attached to the body of Macedonia through the region of Thessaloniki. In the southern part of Chalkidiki, three oblong peninsulas are formed that are from west to east: the peninsula of Kassandra, the peninsula of Sithonia and the peninsula of Mount Athos.
The peninsula of Halkidiki is divided administratively in the prefecture of Halkidiki and in the autonomous monastic state of Mount Athos. The northern part of the peninsula belongs to the prefecture of Thessaloniki
The capital of Halkidiki is Polygyros. Located in the geographic middle of the county, and has about 11,000 inhabitants while the administrative center of Mount Athos is Karyes

Chalkidiki - Wikipedia

Kallithea Chalkidiki's

Kallithea is a city and seat of the Municipal Department of the Municipality of Kassandra Chalkidiki's. Its population is 779 inhabitants (Tr. 2001). The main occupation of the inhabitants are tourism businesses. The city has police, kindergarten and elementary school. It attracts hundreds of tourists every year because of its beaches and developed tourism infrastructure.