It's hard to judge exactly how many players know about GM Island. Some of the older players will remember the flood of trade chat and guild chats whenever a GM was online and visible in GM Island, and those folks who like to mess around with private servers and unexplored places will have at least heard of its existence. However today, with the island being so cordoned off, many players probably are not familiar with the mythical island of the game masters.
GM Island is a piece of land that used to exist in the very upper left hand coordinates of Azeroth, far beyond the reach of players. It exists as an in-game entrance point for Blizzard GMs, and is a relatively mundane place. It has a small keep and a dock, a few trees and bushes, and that's it.
There was a time when players were able to swim out to the island, and that swim took around an hour of hard work. It involved using a level one character constantly casting renew and other healing spells; and the player had to know exactly where to point themselves or risk being hopelessly lost in the vast oceans of Azeroth. The trick used to get there was similar to the one that allowed players to get to the Isle of Quel'Danas on the patch 2.4 PTR back in 2008. It was also possible to water-walk out there, but not much is known anymore about that method, at least publicly.
After the break we'll take a look at a few of the features and lore surrounding GM Island, as well as look at some videos. However, please be forewarned that some of the images and videos in this post are from private servers. Enough legitimate in-game footage simply doesn't exist.
Gallery: GM Island and the Player Jail