Gyms have been mysteriously appearing outside Pokemon Go trainers' homes. This has led to understandable confusion but there is an explanation for it.
One trainer shared that they got invited to a Remote Raid. They accepted but when the timer got down to 20 seconds and nobody else joined, they opted to leave.
Following that they drove 30 minutes across their town to find a brand new gym where they live. It was hosting a Mega Raid and was the exact one they had just been invited to.
Other players have shared similar stories. As you may have guessed, these aren't brand new gyms at all, though.
Instead, they are seemingly 'left over' data from the gym you tried to join for the Remote Raid. "When remote raiding, a fake gym is spawned just for you beyond the horizon for you to raid on it," JaxomNC surmised on Reddit.
"Usually the game will reclaim it once the raid has ended or after capture but, it appears there is sometimes a memory leak and the game will not always not remove it. So you may happen to stumble on several fake gyms packed together if you walk or drive closer to area that's is lying outside your view range in the direction you had the fly-by move to the gym."
Other trainers shared that in their experience the 'fake' gym only gets removed upon restarting the Pokemon Go app. Despite it being there, it cannot be interacted with, simply saying that the gym is out of range.
In the case of this particular Pokemon Go trainer, it doesn't appear to be coincidence that the gym appeared in their changed location. It would have appeared regardless of where they went to.
As usual there is an explanation for this Pokemon Go glitch of sorts. We don't know whether it's intentional, just a by-product of the Remote Raid system or a way to make gathering data within the game more efficient.
In short though, the new gyms spawning outside of your house aren't real!