Stranger Things revealed the real origin of the Upside Down, and it flips a key element of the series on its head.

Fans finally got answered about the Upside Down in Stranger Things season 5. Here's more of what we know about this world.

"Stranger Things" Season 5, Volume 2 finally reveals the origins of the Upside Down. Here’s how the wormhole works, what the ...

However, viewers were kept in the dark until season five's second batch of episodes, now streaming on Netflix.

Here’s how Matt Duffer explained the major turning point in the history of Stranger Things: ...