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.
burnouth03, [HP]~D)I(IN™, Ignored By Society, uhnoo, wwwww369, DoggoficX90 - DAT BOI, tommymccarter.uh, sebastianestrelladiaz, Klaz le petit Führer, gaming55.teo, re15revisited, re15revisited, custom.person, custom.person, absza15, saleemshiyama, kristaps6484, eQuinox, Caboosh, Squeeze, Joe, DRxSoulz, yudoufu147, pazuzu2010, DarkBhawk, fadrizalharist, hyuhyu425, Mister_Amazing_OMFG, Matvil571, raphaelsalzwedel, rmn1981, SpoiledFocus, SneakyBeaky, Denis (Governo Nerd), Romarin, RedNoxious, Hatman, dmitriy-s-98, Chuckle Fuck the Pussy Cat, M3LON_drgaff, de_kebab, Girl Scout Cookies, Waldo, Dave!!!! handicapt again, grimmy45, Piro Winfield, Donald J Trump, HireJockey, anapui37, Gavardo +72 others
