At the beginning of regular gameplay in Grand Theft Auto 5, you play the role of Michael robbing a bank in North Yankton with his accomplices—shooting police and evading a high-speed train in the process. While you do revisit North Yankton during regular gameplay in Los Santos, it's strangely unavailable for online play.
Well, thanks to YouTube user Kronos, you can now exploit a glitch during regular gameplay in order to get into North Yankton for your GTA 5 Online session.
Firstly, you'll need to ask a friend to create an invite-only game online. Once they do this, you'll need to go to regular single-player mode, press start, go to the game tab, and replay Prologue.
Play the mission as you normally would, but instead of shooting it out with the police after opening the garage door, run off to the side and press start instead.
Ask your friend to invite you to their online session. Wherever you respawn, find a helicopter. The easiest way would be to call Merryweather and ask for a pickup.
Once the helicopter arrives, shoot the pilot, steal the helicopter, and fly to the bottom left portion of the map. If you performed everything correctly, you should see floating mountains—which are really outlines of North Yankton.
Fly into the mountains and you'll see the city come to life and build up right before your eyes. Land your helicopter, get out, and explore the hidden city.
If you want a car, you can call your mechanic and have one sent to you, but only if you're on a main road. As for your friend, they'll need to do the exact same thing you did in order to get to North Yankton, instead this time you're doing the inviting.
After that, you can roam around with your buddy and enjoy the secret town of North Yankton.