Alternate point of view:
The only item that can come easily is if it was in our other Earth that is connected to us in a different dimension. A powerful magnetic force can move us back and forth and it is possible that their city jacked up the magnetic force for whatever reason and ended up on our Earth and then went back changing the force...
But if the city buildings are real...you know, Chinese could do that in 200 years...someone should look for any digital signs in Chinese or not......again, it has to do with future magnetic force, our side or their side...