What is an example of dramatic irony in Hamlet?

In Hamlet, Ophelia's madness and death is an example of dramatic irony. When Ophelia dies, the audience is aware that it is due to her father's death and her unrequited love for Hamlet. However, the other characters in the play, such as Claudius and Gertrude, are unaware of these factors and believe that Ophelia has gone mad simply because she can no longer be with Hamlet. This creates a sense of tragic irony as the audience knows more information than the characters and can see the true causes of Ophelia's suffering while the characters themselves remain ignorant.