A short, steep walk up from Via Garibaldi brings you to the top of the old town, where the Cattedrale di San Gerlando has stood since the 11th century, remodelled with Gothic and Baroque additions over the centuries that followed. Its bell tower was never finished, standing at a stubby half-height that somehow adds to the building's character rather than detracting from it.
The real reason to make the climb, though, is the terrace at its base. From here, the view runs out over the newer city spreading down the hillside below, and beyond it across the rolling farmland of the Sicilian interior, with hilltop towns strung along the ridges on a clear day. It's genuinely one of the best photo opportunities in Agrigento, and because it takes a bit of effort to reach, it's usually far quieter than the temples ever are.