The ruins of the fort Sipar located on a small peninsula, situated in the vicinity of Umag, Katoro and between Zambritiey. Depending on the tide peninsula sometimes becomes an island. This is where the ruins of ancient military facilities - Castle Sipar.

The castle was built in the 5th century BC, now its place remained only a scattering of stones. The castle was located on the Cape (200x50 meters) and was built in Roman times, it is easy to prove the features of its foundation. In addition, at this point to everyday objects, coins and fragments of ancient mosaics found in this area.

In 876, the castle has been completely looted and destroyed by pirates under the command of Ban Domagoj. The beach, located near the ruins at the moment chosen by nudists.

Archaeological excavations on the peninsula are still under way, there are many found objects and artifacts testifying to the fact that once there existed a Roman city. One kilometer from the castle ruins were found the remains of villas are equipped with heating, skillful floor mosaics and a large container for storing drinking water.