Take a walk along the waterfront west of downtown Naples and you begin to climb Posillipo Hill. The shore road towers over several dozen "beach homes" (that cost severl million dollars each) and within about a mile from the docks, you have a view worthy of a National Geopgraphic cover picture. The "beach houses" are far below the road and if you are watchful, you can have a picture of Castello D'Ovo centered right under Mt. Visuvius. A bit further along the road and you can take photos centered on the castle with Visuvius on the right and the marinas and port on the left.
It is not a steep walk, but it is a hill, so be careful. The neighborhood is decent and there is a sprinking of mom-and-pop shops along the way for snacks and water. Parking there, as in most of Naples, is abysmal. If walking the long hill is a problem, drive up it to Piazza San Luigi (you can't miss it as it is a parking lot for a movie theater in the middle of a residential area), park there and walk back towards Naples a few hundred yards.
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