Pompeii. She often hosted the gladiator Murranus. After he lost a game of dice to the Seventh Doctor on 23 August 79, she was persuaded to drug the Doctor, but after she did it she barred Murranus from her inn. When Murranus was going to kill the Doctor to regain his "honour", Valeria intervened but they were unable to flee from his gladiators. It was only the timing of the volcanic eruption that allowed them to escape.
She and the Doctor then attempted to escape the city through the volcanic ash, until they ran into Aglea and Popidius. The Doctor left to look for Mel, while Valeria and the other two continued to flee Pompeii. (AUDIO: The Fires of Vulcan)