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.
Tyr, Прасковья, Carl., Nightstorm1003, FelipeColares357, Hashtag_prettykitty, clocky, m.granis[teamPyro], re15revisited, akiramakasuren, Tom, TheRalle, dorianblanchet7, PARADOX, a-zeu, Squeeze, Sherry Stein ❤, BadMikey, Paradise | ✪SrSystem., AGRESSOR, ybica104, rmn1981, barbe.guigui, Rusher, ND17 | Blackwatch, Þ¥ᘂø†† [] [][][][] global olite, TecFreak, alteradler, Griffis520, decadent_uk100, pstratto, Eyehaveyou, SNYPE94, Brightness, Biahwtrooper, Digitallyawesome2, djwildchild, Vanila Drizzle, Doctor Mobius, thog, file_follgen.mp3, Murder Is Pink, Alkaza1996, ♥ ~lil pup~ ♥, falK, gloowb, VecterStroke, Gavin, The Pi_Master, Skull Faced Polish-Hungarian Guy +23 others
