Nearly a city
The centre of Lipari was built to be as similar as possible to a city on the mainland. But its size, the presence of narrow alleys and very few drivable roads, does not make it comparable. However, the difference can be seen in the fewer than 100 inhabitants on many of the other islands to the 12,000 on Lipari.
While you are at the Castle, try to close your eyes and listen: you will hear the coming and going of the hydrofoils, ships and motorboats, but also the vehicles moving in the streets between Marina Lunga and Marina Corta.