Spacious enough to make cave-dwelling seem like a viable accommodation option, this large domed cavern, high on a cliff above the harbour, has been occupied since the last ice age – about 18,000 years. It's open to the sky, so even the most claustrophobic shouldn't baulk at visiting. There's not an awful lot to see here, but information panels (in English and Croatian) explain the ongoing archaeological work taking place. And the views back over the town are wonderful.
It's reached by a very narrow road leading up from the innermost part of the harbour; there are signs but they're hard to spot.