The place, which today is occupied by the castle, was used by the city of Herakleion (Ἡράκλειον) in pre-Christian times. Not only on the top of the castle hill, but also at the foot of the hill, were settlements that were assigned to this ancient city. Around 360 BC Skylax of Karyandar described the place as “the first Macedonian city behind the river Peneios”. The Roman historian Titius Livius has a more accurate position determination. “Between Dion and Tembi lying on a rock,” he described the place, which is identical with the position of the castle. But even earlier, since the Bronze Age, a settlement of the castle hill has been proved.
In the year 430 BC, The Athenians conquered the place to control from here the Thermaean Gulf to their possessions on the Chalkidiki. At the same time, the country’s most popular north-south route runs along the hill. At the beginning of the 3rd century BC, the city and the now established port were destroyed. By what, or by whom, is not exactly known. A short time later the region was conquered by the Romans. In the year 169 BC, from Thessaly coming, they held their camp in the plain between Herakleion and Leivithra before starting their campaign against Macedonia. Of course the outstanding strategic importance of the hill was not hidden from them. Probably from this time comes the acropolis, the upper town, which was surrounded by a low wall. From the time around Christ’s birth to the middle Byzantine epoch, in the 10th century AD, little evidence was found of the events at this time. The name Platamon for the close vicinity of the hill emerges for the first time. With this term Homer referred to a rock surrounded by the sea. In the 12th century, the city of Platamon is described and the castle as such is mentioned for the first time.
In 1204, Franconian knights founded the kingdom of Thessaloniki in the course of their conquest of Constantinople, which also included the castle of Platamon. They finally finished the bulwark, but had to clear it again in 1217 to make way for the Comnenes, a Byzantine aristocracy. The further history of the place remains changing and the castle always finds new masters. At the end of the 14th century the Turks came and were replaced by the Venetians in 1425. They remained until the 400 years of the Turkokratia in Greece began. The last battles took place in the Second World War. New Zealand troops who had moved into this area were bombed.
In this castle we find the 3 main characteristics of the medieval fortresses: the first precinct, the second precinct which constitutes the citadel and the central tower.
The spacious outer wall of the castle has a polygonal shape, is reinforced by towers placed at irregular intervals and is kept in good condition. Its entrance is located on the southeast side while on the same side there is a ruined wall or maybe a propylon (barbikan). The height of the walls reaches 9.5m to the right of the entrance. and 7.5m on the left, while the thickness is between 1.2 and 2m. Between the two gates of the main entrance there was an additional tower, now destroyed.
The 2nd precinct is 6-7m high. and in its northeast corner there is an unusual tower with a square outer perimeter and a circular inner one. This tower has a Byzantine type tiled roof.
On the northeast side rises the majestic central tower of the defense complex with an octagonal shape, 16m high. and 2m thick, the entrance of which was, for security reasons, at a height of 3.45m. from the ground, with access from a wooden staircase.
It has semicircular windows, in one of which there are two openings with a central colonnade decorated with a cross, which probably indicates dating to the period when the castle was repaired by the Byzantine Despotate of Epirus.
In the area of the castle is preserved the church of Agia Paraskevi (the only one of the 5 that existed there before) which during the Turkish occupation had been turned into a mosque.
At the end of the 18th century, Platamonas was an armatoliki, led by Tsaknakis, while Georgakis Olympios was also the commander. In 1770 it was occupied for a short time by the Greeks, as well as in 1825 and 1878. It was bombed by Captain Sachtouris in 1897 and has since been abandoned by the Turks. On April 15-16, 1941, in the area of Platamonas, a New Zealand battalion with German units clashed and the battle ended with the retreat of the New Zealanders. Platamonas Castle (interior) Today it belongs to the jurisdiction of the 9th Ephorate of Byzantine Antiquities and is accessible to the public.