The Prince of Wales Tower, built in the late 12th century, is part of the fortifications that surrounded the city at that time. It also served as a gate, a garrison dwelling, and a grain warehouse. From the seventeenth century, this tower becomes a prison where were locked the false salt workers, salt smugglers. In 1994, the artists Ange Leccia and Jacques Vieille invested this place, following a public commission of contemporary art, by creating two works of art on the theme of confinement, in resonance with the prison's past of the tower. Visits according to program established by the Architecture and Heritage Department of Thouars and during the European Heritage Days.