A region based on Ancient Egypt ( although I don't live in Egypt) would be cool. You can start in a small town which is centered by an Oasis. The biggest city would be one which is built around a huge pyramid. That city would also have a giant Sphinx like thin ( it could be statue of that region's legendary ). Those builds could have a big gym and also serve as the place of commerce and trade.
A big river like the Nile could divide the region like Mt Coronet divides Sinnoh. I don't think this region would have many forest but it would have many deserts and a big cave where you could gather precious stones from for cash.
Also the champion could be a pharaoh
