The myth took off with a blog post presenting peculiar evidence. Alleydoor1 is an unusual door, featuring a Horse or Unicorn texture, first found in Vice Point. Numerous players have put forward their speculations regarding the door, stating that the door is a hint to the myths, based on the fact that it can be found near supposedly paranormal or mythical regions, such as the Docks, Little Haiti, Downtown, the Abandoned Park, the Haunted Mansion, InterGlobal Studios and the Ghost Wall. There is an undisclosed room is situated behind the door, located on the roof of Streetwannabees Leader's Apartment. It's plausible that the Horse or Unicorn was to be featured in the room, but these plans were later canceled.
Alleydoor1 can also be found in GTA San Andreas, at the Missionary Hill TV Tower, as well as K.A.C.C Military Fuels, but doesn't serve any purpose in the game. These two locations have minor myths but are not as haunted as Vice City.