There are sites in and around Hisarönü Limani that have ruins of ancient settlements. One of these is the city of Bybassos, which is situated on top of a hill between the sea and the road. There is a Medieval castle on the hill as well, which was connected with Bybassos, however there isn’t much remaining of this ancient site. You can reach the site of Erine located three km. outside the village of Hisarönü via a forest road. Here, you’ll encounter ruins from both the Hellenistic and Roman Periods. There is yet another site of ruins located between the villages of Hisarönü and Orhaniye. It is the Temple of Hemithea situated on Pazarlik Hill on Eren Mountain.

The goddess Hemithea's Acropolis and Kastabos are close to Orhaniye, and these historic ruins are situated about 760 metres high on the side of a mountain in a small valley. It is possible to visit this settlement from Orhaniye, via a steep road, on foot or by a suitable vehicle. The trip takes about 1 hour. A local driver is recommended. This settlement was in its prime in about 400 B.C, and it was a renowned medical centre where patients were said to be cured in their sleep, but in the 2nd Century B.C. it lost its importance, due to the conquest by Rhodes and later Rome. Parts of the town walls can be seen. The temple was built in Ionian style with some Dorian elements, on top of an older building. It was dedicated to the Goddess Hemithea, and here a sleeping cure was given to the pilgrims. There are scriptures that describe how the ill were bedded in the temple and how the healing took place.

According to mythology, King Staphylus of Rhodes had two daughters, whose names were Molpadia and Parthenos. One day, the King assigned them with the task of protecting a newly discovered sacred wine. A few nights later, some pigs came in and tipped over the kegs of sacred wine while they slept. The girls, who woke up in the midst of all this commotion, were overcome with grief when they saw the wine that they were supposed to protect had spilled all over the place. Fearing their father, the girls committed suicide by leaping off a cliff. However, Apollo found them at the bottom of the precipice and resusitated both of the girls. Although we don’t know what became of Parthenos, Apollo brought Molpadia to Pazarlik above the Gulf of Hisarönü, and left her to her own devices after bestowing her with medical science abilities. It wasn’t too long before this girl, about whom nobody had any idea as to her origins, was observed healing coma patients. She was given the name Hemithea and a temple was erected in her name. Today, it is understood that this temple with its 11 x 6 colonnade, was of the Ionian order and dates from the 4th century B.C. Ancient writer Diodorus mentioned that the Temple of Hemithea was situated at the Pazarlik site whereas this was proven by the English Prof. J. Cook, who uncovered an inscription here. The existence of a theater on the S slope of the hill also indicates that there was habitation here. We know that this site was the ancient city of Kastabos and that the annual Kastabaeia Festival was organized to commemorate the Goddess of Health. It is understood from these 2nd century B.C inscriptions that the summit of Eren Mt. was filled with people who came from faraway places to partake in the festivities, whereas the Hemithea Festival was held here until that century, The inscriptions also imply that the sanctuary began losing its significance later on. Perhaps more suitable terrain was found for the festival, whereas it was continued there.

The Temple of Hemithea, which was founded in the 4th century B.C., did not only belong to Bybassos, but rather to all the cities in the region. It is recorded in the inscriptions that the recommendation for the sanctuary came from someone from Bybassos, but there were also contributions made from cities such as Amos and Hygassos as well. This sanctuary remained a major focal point for 200 years, then it sank into permanent obscurity.