You CAN get real world locations on the Earth map, but you have to do a little work to do it, it is NOT part of the way the game comes, unfortunately.
Go to Civilization Fanatics' Forums>Civilization III> Civ 3-Creation & Customization > Tutorials, Reference & Guide. There, you will see Marla Singers thread entitled "How to play on Earth Map with all correct locations in 30sec". Read it , download the attached file and run it, and your there. You should also be able to customise the game as you would normally, IIRC.
Good luck. Sorry I didn't answer your PM unitl late last night, I didn't see it unitl then ... I was busy conquering the French all weekend, rather then being on-line at the forum. Joan just WOULDN"T trade luxuries with me, for a reasonable cost, not even for a questionable reasonable cost ... now I have them for free. Sorry, Ms. d'Arc ... bad business decision.