The Gâche Tower was built under Pope Innocent VI, at the same time as Saint Laurent Tower which fortifies the southeast corner of the Palace. The Gâche Tower encloses the Grands Dignitaries wing to the south.
This Tower became the highest observation point in the Palace, for it had a third floor where the watchmen were posted to guard the Palace. This led to the name of the tower, for it was referred to as the agacho tower. Agacho in Provençal means: “the place from where one observes”.