Minerva. A South Pacific atoll that was underwater at high tide, and unclaimed by any nation. The plan was to build a seawall and make dry land. It would be a freeport which would be the non tax source of income.
The organizers produced a 'collectible' coin as a fund raiser (No, I didn't buy one)
The dream ended when the king of Tonga, at the head of what news reports at the time described as a 'war canoe' arrived, claimed the atoll for his kingdom, and drove the new country project people away.