The ruins of Villa Giulia, on the northern end of Isola d' Ventotene.
As the daughter of Augustus, mother of two of his heirs, Lucius and Gaius, and wife of another, Tiberius, it must have seemed to Julia that her future was assured. Yet in 2 BC she was arrested for adultery and treason; Augustus sent her a letter in Tiberius' name declaring the marriage null and void. Augustus asserted in public that she had been plotting against the life of her own father . Though at the time Augustus had been passing legislation to promote family values, he likely knew of her intrigues with the other men (his knowledge of the conspiracy shows he knew of their activities for some time), but loved her too much to accuse her of it.
Several of her supposed accomplices were exiled, most notably Sempronius Gracchus, while Iullus Antonius (son of Mark Antony and Fulvia) was forced to commit suicide. It is hard to reconstruct what actually happened, but it was proved that she had taken part in nightly drinking parties on the Roman Forum and that Iullus Antonius was certainly her lover. Many other men were also reported to have enjoyed her favors, but this may have been gossip.
More on Giulia can be seen here.