Mljet – really gorgeous, not built up, direct catamaran from Dubrovnik and with a beautiful lake to swim in
Hvar is very cool but as you say it’s not that easy to get to from Dubrovnik. In summer the Dubrovnik-Rijeka ferry calls in Stari Grad on Hvar but only goes twice a week and takes about 6-8 hours. Or you take a bus up along the coast to Split (about five hours) and then a ferry from there, which would be another couple of hours.
But there are some brilliant islands nearer to Dubrovnik which sound like they might be a better bet if you’re on a city break. The Elaphite islands are gorgeous and very chilled, with some good walks and cycle rides and decent beaches, and won’t take much more than an hour or so to reach from Dubrovnik. A bit further away there’s Mljet, which has a national park with some great lakes for bathing.
If you’re after somewhere a bit livelier, Korcula is about midway between Dubrovnik and Hvar and has some good restaurants, amazing beaches, sword dance festivals and vampires – what more could you want?
How about Mljet? It’s stunning and not too far away from Dubrovnik. Or you could visit Korcula
via Mali Ston (for some oyster tasting en route).
I’m not sure whether you’re looking for an island to stay over on, but we visited Lokrum (which is very close to Dubrovnik) for swimming, cocktails and a picnic. It’s beautiful there and has lot’s of caves and gardens to explore.
Definitely Lopud. One of the small Elefite islands just an hour away from Dubrovnik, it’s small, cute, car-free and has one of the very few sandy beaches along this part of the coast. You can hike around too – paths through the scrubland lead to ruined mansions, once owned by rich merchants from the city. There are plenty of good B&Bs and apartments (check out www.lopud.eu for handy listings and maps), and good restaurants. Daytrippers from the city make the main village and beach busy in high summer between 10am-6pm, otherwise it’s quite calm.
Time the ferries right and you can do a daytrip to Sipan, the bucolic next island. There you can rent a bike and cycle 7km across the island, visiting fortified churches and an old monastery along the way.
In summer I’ve used Lopud as a relaxing base for visiting Dubrovnik – prices and food are better, less crowds.