Stairs and secret passages

In the thickness of the fortress walls, there are quite steep stairs and narrow passages. Those that are open to public have railings and lighting, but there are also a number of locked ones. They also talk about the ancient underground passage from the castle to the city's cathedral, built during the time of the ever-memorable King Eric XIV. They say at the end of the 19th century it was still possible to get from the city to the castle.