与論島 (Yoronjima)
Twenty-two kilometers north of Cape Hedo, the northernmost point on Okinawa, lies Yoron Jima. Despite it's close proximity to Okinawa's main island and it's status as an island in the Ryukyu island chain, it actually is the southernmost island in Kagoshima Prefecture, making it the farthest south you can go while still remaining on what is considered mainland Japan.
There's not a single fast food restaurant, 7-11, Family Mart, Lawson, or Coco's here. And with a population of only 6,000 there's probably more bugs and geckos than actual people here. It's the perfect place to get away from it all.