Klis Fortress is a medieval castle situated on a rocky hill overlooking the town of Klis in Croatia. The fortress dates back to the 2nd century BC, when it was first used by the Illyrian tribe of Dalmatae. Later, it was conquered and rebuilt by the Romans, who used it as a military camp. In the Middle Ages, the fortress was an important stronghold for Croatian kings, and it played a crucial role in the defense against the Ottoman Turks.

The fortress has a long and interesting history, having been destroyed and rebuilt several times over the centuries. Its present form dates back to the 15th century, when it was extensively renovated by the Croatian nobleman Juraj Šubić. The fortress was further expanded and strengthened during the 16th and 17th centuries, when it became an important military stronghold in the fight against the Ottoman Turks.

Today, Klis Fortress is a popular tourist attraction, offering visitors a glimpse into Croatia's rich history and culture. The fortress has been featured in several films and TV shows, including the hit HBO series "Game of Thrones", which used it as a filming location for several episodes. Visitors can explore the fortress's many towers, walls, and gates, and enjoy panoramic views of the surrounding countryside. There is also a small museum on site, which houses a collection of weapons, armor, and other artifacts from the fortress's long and storied history.