
United States: Stranger ThingsStone Mountain Park
Nestled in over 3000 acres of parkland, Stone Mountain Park is Georgia's most visited attraction. It features a variety of attractions, entertainment and recreation activities, such as a treetop walk, a 4D cinema and a scenic railroad.
The railway tracks that cut through the park appear in Season 1, Episode 5: The Flea and the Acrobat when the boys are first seen walking along these tracks with Eleven.

Lucas and Dustin discuss how to find the gate to the Upside Down by using their compasses.
In Season 2, Dustin and Steve walk along the same tracks in search of Dustin's escaped pet demogorgon, to no avail.
In Episode 8: The Mind Flayer, they try again, this time with the help of their friends Lucas and Max.
The location is very recognisable and easy to find: Follow the marked Cherokee Loop Trail until you reach the following coordinate: 33.808399, -84.139244.

Here's Tori and Ash from The Upside Down podcast on location.
Key Scenes
Watch
About the Story - Season 1:
'Stranger Things' is set in 1983 Indiana, where a young boy vanishes into thin air. As friends, family and local police search for answers, they are drawn into an extraordinary mystery involving top-secret government experiments, terrifying supernatural forces and one very strange little girl.
Map
The location is on the Cherokee Trail at the following coordinates: 33.808399, -84.139244.