Overview
The rock of Megaride carried a Roman villa, then a monastery, then the Norman fortress whose walls are still the outline. Every ruler of Naples since has rebuilt part of it, so the fabric reads as a stack of centuries rather than one castle. Entry is free, the ramps run up to open terraces, and the fishing village of Borgo Marinari sits in the harbour at its foot.
Highlights
Go up at the end of the day for the view along the bay to Vesuvius, which is the classic Naples sightline. The castle closes earlier than its terraces suggest, so check the hour before climbing. Borgo Marinari below is a working marina with restaurants on the quay; it is touristed but the setting is the point.