There's a special place in my heart for this game, due entirely to its bugs.
In the context of the game, the player was Christopher Columbus exploring the Americas. The player was supposed to trade peacefully with the natives.
However, instead of trading peacefully, if you systematically massacred all the natives, you could steal all their gold.
If you did this, the Crown would rap you on the knuckles. However, the amount of gold stolen was so massive that it had no impact on the game. You were essentially rewarded for genocide.
It was a great deal of fun.
Seven Cities of Gold is now abandonware and is available for download from many sources for many architectures. To my knowledge, the C=64 version is the only version that has the bugs.
One such download location is here:
The game still runs under emulation: