Whether it’s threading around jagged mountain peaks, puddle-hopping a chain of far-flung isles, or making the final approach to that exclusive lodge left off every map, travel to some of the world’s most pristine locations is often possible only by small aircraft. Yet such isolated and difficult terrain is what makes these oases so relatively untouched in the first place—and another reason why they’re not to be missed. Here, four destinations best visited by bush plane.