I feel like i must be failing with search keywords not being able to find a topic about this, but is there any way to reveal the whole map?

I was experimenting with higher difficulty setting AI's, and I just had a game where on turn 21 the kingdom report said my neighbor had a net income of 50.4 .  Which is pretty crazy to have by turn 21.  Wondering if the map just spawned him next to 10 gold mines, or if higher difficulty just gives over the top bonuses to computers.

(needless to say with an income of that much he had a huge army that killed me)