Mirabela Fortress is located at the top of the historic center of Omish and is one of the symbols of the city. It was built in the 13th century as a scout from the enemy. Here, Omish pirates followed the enemy and could set off an alarm even before enemy ships could approach the city. The fortress offers a view of the entire Omish and the Brach channel. The fortress consists of 4 floors, and at the top is a beautiful belvedere. The fortress is reached from the old town. It takes about 10 minutes to walk, but one part is steeper.