One of the inspirations for the fantasy island of Dinotopia is a real place called North Sentinel Island.
|North Sentinel Island (left) and Dinotopia|
The island has enjoyed this condition for a variety of unusual circumstances. The entire coastline is surrounded by impassable coral reefs. There is no reliable harbor. There's nothing on the island worth claiming by more powerful nations. The view on Google Earth shows solid tree cover and no sign of roads, settlement, or agriculture.
However, there appear to be between 50 and 400 people living there. No one knows for sure how many. They speak a language that no one else understands. They use and cherish fire, but it is believed they don't know how to make it. They haven't developed the paddle, so they can't power their dugouts to the nearby Andaman Islands, and have never developed trade. Two cargo ships, the MV Rusley and MV Primrose grounded on the coast in 1977 and 1981. Most of the crew was rescued, and the inhabitants scavenged iron from the wrecks for arrowheads.
The Sentinelese fiercely rebuff all attempted visits or gifts. If anyone tries to greet them from the outside world, nearly naked warriors appear on the beach and attack with spears and arrows. Despite several attempts to make contact, usually by leaving gifts on the beach, the Indian government has decided to leave them undisturbed, and now arrests anyone who attempts to approach the island.
What stories do they tell each other about the few helicopters that have hovered briefly over their beaches? What have they made from the parts they salvaged from the wrecked ships? What do they know that we have forgotten?
Wikipedia on North Sentinel Island
Mental Floss: The Stone Age People of North Sentinel Island