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

In trying to find out more about the supposed shield generator around the Upside Down, Dustin discovers a notebook from Dr.

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: ...

It's also the home of demons, so it makes a ton of sense that the Duffer Brothers would incorporate this into the final ...

After four-and-a-half seasons of questions prompted by “Stranger Things,” in Volume 2 of the show’s fifth and final season, ...

On Christmas Day, Stranger Things fans finally discovered the series-long mystery of the Upside Down, an alternate dimension ...