To get to Mljet from us it takes approx 2hrs, by car and ferry, a relatively easy coastal journey by car or there are tourist excursions from Dubrovnik along with a fast Catamaran service, daily from June to October ( £5 for a return journey, giving you about 5 hrs there).
Mljet is one of the eight National Parks in Croatia, famous for its lush vegetation, pine forests, saltwater and mud lakes. The National Park is in the North West western part of the island. The two salt lakes, stretching 4km, are in the north of the island Veliko jezero (the Big Lake), with smaller Melita island in the middle of it, with a 12th Century Benedictine monastery, now a cafe and Malo jezero (the Small Lake). Both favourite swimming spots for locals and visitors. Both lakes are encircled with well-marked paths to walk round or a cycle can be rented in Pomena, Polace and at Mali Most. If preferred you can rent a kayak at Mali Most.
There are numerous small pebble beaches and swimming spots round the island however, Saplunara beach is the only sandy beach on the island.
Mljet is good to visit in the cooler months as the sea here is warmer than on the main land and the ferries from Dubrovnik do run all year, though not as frequently.