By the 24th century, Hanon IV has developed to the equivalent of the Pliocene Age on Earth. The planet is also home to a species of proto-humanoids who are at a cave-man stage of development, having established their culture in small tribes.
In 2372, the crew of the Federation starship USS Voyager were marooned on Hanon IV after First Maje Jal Culluh had taken over the vessel. With no advanced Federation technology available to them, the Voyager crew had to live like cave men, crafting crude weapons and foraging off the land. Thankfully, their stay on Hanon IV was a short one, as Tom Paris, The Doctor and Lon Suder had led a combined assault both inside and outside Voyager and managed to retake the ship with the aid of the Talaxians. (VOY episode: "Basics")