Marina Grande, Sorrento

What Seaglassmap found here

The old fishing harbour below Sorrento, still a working corner rather than a resort beach. A collector who spent a few hours along the waterfront here came away with olive glass so dark it reads as black until you hold it up, along with a piece of wired window glass. Sorrento's main beaches have a reputation for giving up very little, so it is the harbour itself that is worth your time.