Later on, during the Byzantine period, the altar had been abandoned and when the Knights of the Order of St. John conquered the island, they used some architectural parts for the construction of the castle.
The frieze of the altar is dated back to the end of the 2nd century b.C. and now it is housed in the castle. It presents scenes from the Amazon war and a troupe of Dionysus, with maenads and satyrs.
Only a rectangular groundwork is well preserved today, along with the uphill entrance and a vertical stone wall.
At the same area there has been found an older temple in Doric style, possibly this too of Dionysus, and two rectangular constructions, possibly bases for statues. Excavations were carried out by Italian scholars, during 1930’s, but due to the following war nothing was published. Only recently the Greek professor N. Stambolidis has studied the sculptures of the altar.