Final answer:
In the play 'Hamlet' by William Shakespeare, the main character, Hamlet, is imprisoned in the castle of Elsinore, Denmark.
Step-by-step explanation:
In the play 'Hamlet' by William Shakespeare, the main character, Hamlet, is imprisoned in the castle of Elsinore, Denmark. Although there isn't a specific location mentioned within the text, the play refers to Elsinore as a prison and Hamlet's own words suggest that he feels trapped and confined.