As I stated in the article of Namrun Castle, it seems that there used to be a defensive line. Sinap Castle is on the defensive line it seems. It is the second biggest castle of the region but due to careless, it became a ruin today;
This region was a strategically important in middle age. So it is thought that it was built in 10th or 11th century AD. It has an eye contact with Namrun(İllibru) Castle. Its task was to control and to dominate the region.
Mersin is an important region for history. It is certain that most of the historical monuments expect care from us and authorities. When we protect them, we can make them great again.