Knin Fortress is a military fortress formed by early Croatian cultural heritage in the ninth century, and is located on the south side of Mount Spas, which dominates Knin and its surroundings and offers beautiful views from all sides. The fortress is one of the largest Croatian fortifications and the second largest military fortress in The construction of the fortress began in the 9th century, during the Early Croatian Republic, and some Croatian kings had the capital Knin intermittently, while King Dmitar Zvonimir even kept it permanent.
The fortress consists of five connected parts located 345 m above sea level and about 100 m above the town of Knin. It is 470 m long and 110 m wide at the highest part. The defensive walls, about 2 km long, enclose the fortress on all sides, in several places up to 20 m high. The fortress is a living cultural monument and includes a museum, exhibition galleries and restaurant, so it is the main label of Knin's cultural tourism. It is open from March 16 to October 31 every day from 7 am to 7 pm, and out of season from 7 am to 3 pm.