The ruins of the Fort can be reached is located on a small Peninsula, located in the vicinity of Umag, between Katoro and Zambratija. Depending on the time of the tides Peninsula sometimes becomes an island. Here are preserved the ruins of an ancient military installation - castle of Sipar.

The castle was built in the 5th century BC, now in its place was only a scattering of stones. The castle was situated on a promontory (200x50 meters) and was built during the Roman Empire, which is easily proved by the characteristics of its Foundation. In addition, to this point, household items, coins and fragments of ancient mosaics discovered in the area.

In 876 the castle was completely destroyed by the pirates, commanded the pan Domagoj. The beach, located close to the ruins, currently popular with nudists.

Archaeological excavations on the territory of the Peninsula is still under way, there were found many objects and artifacts, attesting to the fact that there once existed an ancient Roman city. One kilometer from the castle ruins were found the remains of the Villa is equipped with heating, a skilled floor mosaics and a large capacity for storing drinking water.