The fortress has seen numerous battles, right from 1308 till the Second World War. It was even used as a prison for decades. When the great fire of 1624 destroyed many buildings and structures in the city, the then monarch, King Christian IV, got the whole city (including the castle) rebuilt and remodelled. What you see now is the renovated castle with stunning towers, halls, and chambers. Many major events and concerts are conducted at the castle premises. Guided tours are available in the summers.