One of the most bizarre places in the entire Red and Blue game would have to be Glitch City. Technically, Glitch City can be any of the cities that the player has visited, due to how the game handles travel in between two places. The ‘gateways’ between two places in the game is called a ‘warp’, and by exploiting the step timer of the Safari Zone, it’s possible to break these warps, causing the player to enter into a corrupted version of a city, hence Glitch City. There are different appearances for Glitch City, but they all share the characteristics of randomly assorted tiles and invisible walls. Unless the player has a Pokemon with Fly or Teleport, they are essentially stuck in the city until reset. In Pokemon Yellow, Pikachu’s happiness can be reset upon entering Glitch City. However in Generation III and onward, the mechanic used to travel between two maps was changed, thus removing any chance of entering Glitch City in games after Gold, Silver, and Crystal.
To enter into Glitch City, one must be prepared by having either a Flying or Teleporting Pokemon (with a Pokemon Center recently visited). Also be aware that there are certain places that will not trigger Glitch City to be entered. These places include the insides of buildings or any city itself (however you can do this in Cinnabar Island if you surf along the eastern coast), Begin by heading to the Safari Zone, and entering in as normal. Walk around a bit in the Safari Zone to use up some of your steps, before attempting to leave the zone. When the guard asks if the player wants to leave, reply with no and return back into the Safari Zone area. Immediately save the game, reset, and attempt to exit again. Instead of being asked the same question, the guard will ask you if you wish to play the Safari game (as if you had just entered in from the other side). Respond with no, and walk out of the building. Once outside, immediately fly to anywhere, and begin walking in any route. While you are outside of the Safari Zone, the game still considers you in the game, as it counts your steps as if you were. Once you run out of steps, a message will pop up saying that you have ‘run out of time’, and you’ll be teleported to the Safari Zone gate. Walk outside, and you’ll find yourself standing in the center of Glitch City.
Apart from a lot of distorted graphics, there normally isn’t much purpose to traveling to Glitch City. However by following some additional steps, it’s possible to enable the player to walk through walls, and potentially be able to enter into the Elite Four without having all the badges. First, make sure that you only have one strong Pokemon on hand that can Fly, and make sure that you visit a Pokemon Center for a place you want to walk around in with your trick (so if you want to skip to the Elite Four, visit the Pokemon Center in Viridian City). Find an area as well which has a Pokemon that can poison yours, and a ledge that can be jumped off of (your one Pokemon will help with being able to get here). Once these two things are secured, proceed to begin with the Glitch City steps again, stopping once the player has left the Safari Zone gate with the steps still being counted down. Fly to your designated area, and make sure to carefully keep track of every step that is taken, as you will need to end your last step as you’re jumping over a ledge. While in your area, get your Pokemon poisoned as well. On your last step, jump the ledge, and in the middle of the jump you should be prompted again with the ‘time’s up’ message. Once inside the gate, you’ll be able to walk through walls, but be sure not to enter into the blacked out areas, or leave the building. Walk around until your Pokemon faints, which will cause you to be returned to the Pokemon Center that was last visited. Once you finish in the Pokemon Center, you will be able to walk through walls outside of the building. You can use Fly or Teleport, but if you get into any fights or enter any buildings, you will lose the ability to walk through walls.