If I was a multi-billionaire, I'd buy a whole lot of property in West Texas or one of the more southern Great Plains states (we're talking property the size of Belgium) and turn it into a giant African game preserve. Elephants, Rhinos, Springbok, Hyenas, Lions, Cheetahs etc.
Then, I'd invest in cloning mammoths, sabertoothed cats and other extinct mega-fauna.
That, and hire tens of thousands of people to re-create famous historical battles. So, do you want to be Wellington or Napolean this time?
Why not just buy Belgium? Better chocolate, though it does come with Belgians. Ugh.