In the cove Sepen, just a few kilometres by air to the south of Omišalj, there is an inexhaustible site of archaeological heritage. The first traces of settling in the area date back into the 1st century when the Roman town Fulfinum emerged. Its emergence is related to the construction of the city for the retired Roman soldiers during the Flavian dynasty. A good geographical position caused the development of seafaring and trade. The past archaeological research discovered the city forum, the heart of every city from the Roman age, the centre of the social and religious life of the Romans. Here, only fifty meters from the sea, is where the foundations of the temple, the civilian basilica and the commercial edifices (tabernae) were found. In one moment during the 3rd century, the city simply died out, at least when it comes to its original monumental form. Still, life continued. Traces of more modest settlement of the area were found, probably connected with the port which is still in function.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.