We took a taxi to explore the town. It was so hot that we did not dare climb up the stairs to the Acropolis. We saw several people slip and fall on marble stairs at other sites.
We took a taxi to Ephesus for EUR 70 round-trip. The driver waited for us at the site. It was fully worth is. Afterwards we explored Kusadasi a Little. A very clean and nice harbor town.
We took a Sightseeing bus. Naples was very disappointing: dirty, with graffity everywhere (even on historical buildings) and badly organised. Our boat trip to Capri was also not really worth the trouble.
You can walk around and explore the town yourself without any problem.