At the top of the Campanile there is a glass trapdoor you can actually see the bells through. I was lucky enough to go on a tour up the Campanile with somebody from the Mandela Bay Development Agency who was in charge of the renovations and he opened the door for me and allowed me to stick my camera inside.
A carillon is a musical instrument that is typically housed in the bell tower of a church or municipal building. The instrument consists of at least 23 cast bronze, cup-shaped bells, which are played serially to produce a melody, or sounded together to play a chord. A carillon-like instrument with fewer than 23 bells is called a chime.