Everyone else here mentioned the stairs so I'll concur that yes, there are a lot of stairs, but if you can handle that I'd say it's actually a plus of the overall experience. Caterina's apartment is huge and set in a narrow stairway that's quiet and beautiful. Also, the funicular is two minutes away and an easy option for getting up and down (thanks to Caterina for extremely helpful directions navigating to the apt). We loved Naples and had a great stay.