I quite like the Gobi, but for sheer size you can't beat the Sahara. Can be a bit dry though. Oh and you can't get them in supermarkets, it's a disgrace.
You've brought up something here that's been worrying me for years. Geographical retail purchases are just not catering for the desert lovers amongst us. You can get Ocean finance. William Hill, Mountain Warehouse and the over the top River Island are other examples and don't get me started on Sky. Where the hell , as you say, do we get large, dry tracts of land?
