The castle at is just south of Gülnar district of Mersin Province. It is on a 700-metre (2,300 ft) hill at the west of the road between Gülnar and Aydıncık. Visitors can reach the castle either from Gülnar by a 11 kilometres (6.8 mi) road or from Aydıncık by a 35 kilometres (22 mi) road. From Mersin the total distance (over Gülnar) is about 165 kilometres (103 mi).
After the collapse of Hittite Empire, Anatolia lived in a period of turmoil. Many small states emerged and one of them was Pirandu in South Anatolia established by the Luwian people at the west of the Göksu River at around 7th century BC. The capital of Pirundu was Kirshu . However in the 6th century BC Kirshu was sacked by the Babylon Emperor Neriglissar. After Babylon was defeated by Persians, Kirshu came under Achaemenid rule and after Achaemenid Empire was defeated by Alexander III of Macedon, Kirshu was incorporated in to the realm of Ptolemaic dynasty in Egypt and Seleucid Empire.
The plan of the fortification is roughly rectangular the longer dimension being north to south direction. The total area is 750 x 150 m2 (2460 x 490 ft2) In the fortification the military units were at the north side of the hill and the only entrance to castle was via the gate at the north east corner. The palace was at the middle. A public treasure consisting 5215 coins of various Hellenistic states have been unearthed in this palace. These coins are now exhibited in Silifke museum. Another important find is a stamp of Muwatalli II, which is surprising because Hittites lived much before Pirundu. At the south there is a wide wellhole, the function of which is debatable. It might either be a cistern or an altar or may even be a secret passage. At the present, excavations down to 23 metres (75 ft) gave no clue.