Ustica is a little jewel off the coast of Palermo, reachable in less than an hour and a half by the rapid Liberty Lines passenger hydrofoil. (You need to book your place on this a good few weeks in advance of your trip to Ustica to be assurred of a place during the summer season June to August).
If you are fond of diving - I need say no more - Ustica is Diving Central exploring the grottos and caves which abound around this Basalt outcrop at the Northern edge of the Mediterranean.
However if what you are wanting is a Quiet, beautiful, scenic, semi rustic location - where you can enjoy sunshine, always with the refreshment of a light sea breeze which is so wonderful alongside the heat - some gloriously fresh and clean sea bathing - the lighthouse is the number one place to swim from, but also the grottos which abound near the pine forest walk to the village below the stone lodge you will be accomodated in (get your wonderfully kind host Lubja's mum to show you), and some fine restaurants as well as happy pizza houses - in the main village - to enjoy sea food at its very freshest - in off fishermans' boats in the morning, and the sweetest naturally perfumed Ricotta from local farmers available for your own table of delights when you decide to cook for yourself - then this is the most wonderful holiday break for you - you will be utterly restored after only a few days break and ready for the next thing life holds for you.
You need to have a certain level of fitness, and psychological flexibility to really enjoy - but with that said - and noting that this is really like a Skye in the Med as my best way of capturing what Ustica offers - you have found pure holiday gold. (ask Rosella for some swimming towels if you are just bringing hand luggage on Ryan Air or Easy Jet - otherwise snorkels and all other beach attire available in the small boutique shops in the village centre by the port).