This tower is named after the knight Dalibor of Kozojedy, imprisoned here in 1498 for supporting a peasant rebellion, and later executed. According to legend, he played a violin that could be heard throughout the castle; composer Bedřich Smetana based his 1868 opera Dalibor on the tale. You can peer into the bottle dungeon, and see a small display of torture instruments.
More interesting than the tower is the modern bronze sculpture Parable with a Skull , by Jaroslav Róna (who also created the Franz Kafka Monument in Josefov). Supposedly inspired by one of Kafka’s characters, it shows a prostrate human figure bearing a giant skull on its back (you can still see homeless people in Prague begging in this traditional but submissive and rather despairing posture).