This download looks like a map. You need to place it in your maps folder inside the Garry's Mod folder.
You should end up with a directory structure similar to below
Don't know where the Garry's Mod folder is or how to extract zip files? See more useful installation tips.
WilliamTheGamer101, jean, Holly Molly, HeloniM, VonMarlok, napstaplayer5, lorenzopinheiro12, gabor.takacs07, giankrouz, yusufkartal52, TITLE KUING, FD Fake God, マフィア, Matheus0067BR, ah470020, GyVasss, Ben.Memo, 우쓰우쓰, asd124, demomanyt YEET :p, orhunt49, Manaucita, MrCowdisease, emilc2509 SKINHUB.COM, kaanoguzhanyildirim, cihan.seven.67, Katil Civciv, yusufbaba, ッPixッ, YaGenemi Amcalar, N0rak, anettjoy, bardiaal00, halilkose731, UnikornPorn69, LULDAMER2018, assassin.yt.010203, DantE, hayhay56lamghari, nguyenanhkiet56789, HaYtReZ, Tomekpl, jeff55, Mobile48, WinDiMoZ, AtoD, BIG MOUTH NGGER, MiziKun, amirmohamadsarhangy, [kami NOEYBNK48] +6646 others
