So why aren't there pogodas throughout California.
Columbus told the world about the results of his exploration and it changed the world. The Chinese may have gotten here before him - and after the Vikings - but their arrival is only meaningful as a curiousity. Columbus' expedition, and those who followed him, mattered.
A number of South American early cultures have markedly Asian looking art and jade figures and ornaments..a number of scupted heads that look very oriental. Personally, I think early man traveled far more extensively than we imagine, and in the absence of satellite dishes and cell phones ended up in places from which they couldn't return home.