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.
willianlsobogado, Tylor.A, utsuCUL, adextorex576mlg, FrightFulSpy_Gaming, oof, wasd1235, DJ Octavio, PauloSenninBR, luis15cn, Dude Animation, 姜饼人, mrdiegomx98, facuchini19_12, yesussalas432, jadeyu12345, 1825811780, jepotikots, cristianmoscoso, Nerzjeans1511, burritocats42, jurratike, 1228256275, javierlarreynaga224, sebasalta007, marlinventura01, d.moumen.y2, nurs80, andrecuncev, Archimedes, jjvictorbonnie232425, morgan203, AnimalCracker66, ivanyksemen, 123macaocp, PedroHRM10, Pedrostin, ♠♨RTD♨♠TastyTony, ionutalina1, ficacar7, Alien, TreeTale, MikeOfWind, antestrada01, Xyoutuber4KX, Anonymous, NotGame889, RickDracul, jorgerico007.jr, nadyes +718 others
