In august 2005 I spent eight days in papua new guinea (png) with charity airline maf (mission aviation fellowship), who fly aid and church workers around some of the most inhospitable parts of the world.
png has some of the most extreme flying anywhere - many of the airstrips are carved into hillsides, and are steep slopes where you land uphill and take off back down the slope. For many of the small highland villages, these flights maybe once or twice a week are their only contact with the wider world. Airstrips that are only ten minutes flying time apart can take two days walking, due to the incredible terrain.