Proper grammar/form (?) would be El Dorado Pequeno, which, after looking at my Spanish dictionary means literally, The Golden Little. "El DOrado" is, however, "the legendary city of gold." I'd suggest "El Doradito" (the "ito" signifying "little"... among other things), though I'm in danger of making up words and it doesn't sound that pretty. *sigh* Okay, sorry, I'm really leaving this up to the native speakers now.
Sara