The south transept of St Mary's Newport contains a late 13th century portable altar known as the Newport Chest. A false bottom conceals a secret compartment. The lid is raised to form a reredos and the panel depicts from left to right, St Peter, the Virgin Mary, the Crucifixion, St John and St Paul. These are some of the earliest known oil paintings on wood. The exterior decorations suggest a Byzantium influence - the chest may have served in the Crusades.