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.
pyro_main2001, 7ouda, Edelme_Alllado, Kazut0_Desu, joaquinpelaez2010, diegomartingt10, sergiovillaperi, pan sensual, lenfire850, NemesisWolf112, WHITE, jeanpaul_plays, Niko!, Fucko Boingo, austyboy82, Alright Pinhead | trade.tf, juandiegobustos009, ramiroduran39, Gameonguys1, dadoko1774, JKG708, jsrivera10, Adobe photoshop csgohandouts.com, oghhmed, [email protected], Tamamo no Mae~, Tomekiac78, Zezztah, menT, Enzou, jonathonmaldonado59, MosheVilliers, itsmakeshift14, Xemith, Luisbarth79, Luisbarth79, sergiobustamante, ariano113, -Phoenix-, Wormhole Gatekeeper, Brainles5, petethepyropanda, doodaloo, minionguy, phoenixfirekreg, [POOT] Krankxl, Rügenwalder Prinz, lion12142, Gravity, bm4j49e +27 others
