The Campanile di San Giovanni is the surviving bell tower of Caltanissetta's old Church of San Giovanni. It is a small stop, but a good one for anyone interested in the city's older layers: pointed arches, decorative archivolts, and a Catalan-style mullioned window survive in the stonework.
You do not need long here. Fold it into a walk through the historic centre rather than treating it as a destination on its own.