Under the sea

Darling it's better, down where it's wetter take it from me....

What's that, Mr. Iger? Stop singing from your company's musicals? Fine.

361 million square kilometers of the Earth's surface are covered in salty water. This represents 71% of the total area. They are contiguous with each other, and the only area on earth not claimed by any nation yet. (Well...the area near some countries is claimed, but if you want unclaimed area, you'll need to go deep into the ocean.)

While aspiring libertarians talk about utilizing this through a fleet of little boats, a more permanent, and less nauseating, form of living could be established through enormous domes built on the seafloor and then pressurized with air. An airlock would allow access through submarine, and if the roof of this dome were made of transparent materials, it would be absolutely spectacular. Some farming, or water electrolysis, would be necessary to keep up the supply of breathable oxygen. Farming is probably the best strategy, as it neutralizes waste, produces oxygen, and produces food, thus making the habitat self-sustainable.

Of course, if the habitat is more than 200 meters deep, likely considering where it would have to be to be independent of other countries, it will also need independent lighting, electric power sources, and a whole mess more of complications.

Now if you need me, I'll be listening to Bach's Wachet Auf...