The three-mile Lavena Coastal Walk on Taveuni Island begins at rustic Lavena Lodge and traces a white-sand-fringed blue lagoon, then a black-sand beach, past friendly villages before climbing through forestland to Wainibau Falls. Plunge into the natural swimming pool below the falls in a landscape that looks positively primeval. You can hire a guide for this walk or go it alone by taking a taxi from anywhere on Taveuni to the lodge. (Note that you'll be tackling a few fairly easy river crossings, so expect to get wet.) Allot time to swim or snorkel off Lavena Point, or arrange a guided kayak trip along the coast.