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.
RLManiac7, harmoniks890, agus.s_de_vp, aleksandriec1, corachita2018, adamis562, Lytii_Nasvai, NightDragon, yufa, Shivkovski, Bardock, Nekyto, alexisdovlatis, rayansouissi953, Poltergeist, wolverine041269, cevidi.oliveira753, valentin.dhorme03, samiabenamar58, guncef2002, -Typical- GaMiX-fr, zehra_klkci11, zehra_klkci11, Raptor216, cris033, proreach1, Soldado Nazus, -RHC- Funny_TV, ledesmajayden0, snyxnon, hassan.lattakiaa, stefanomattina21, Yo - lo, ludmomac, SLauGHTeR, banettetejode.yt.2.0, banettetejode.yt.2.0, xGlassGhost, qweqweqweqqweqweqweq, juanmattos120, ThehdFrag, obibest2016, mario.meme.exe, rohanpark871, [WRP] PinguKing, player1234, ONLYGAMES34544 MOD DE ETS2, CatmanOrigins, ♥Sushi♥, Shwiki +396 others
