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.
Лохматый, ✪✪, mjoaquintt, aturskis, kenayramoscordova1, alessio3521, guimaraes.moreira, roshan800, TadosiukaS, adanielv24, MemeLord420, jirkagurgul, KageKao, Mattricci1, azov_wars, Tiranoplays2, bacon., twitch.tv/nickdagamer9, emicedano, itsbyluke, riyadhbr18, rajabaral, Mondialul23, deadstreet575, Criticalgunman, kiapekenmika, jeremiahfasterbrown, BelieveJesus&followHim, zugdidihostel, majda.mirda, zigortfurkan, _Bullet_Sky, bm.patrik, Harambe Uchiha, renan3989, juanmattos120, yassingueblauoi, kenzulleheb, Marko, CargoMeteore782, francismoving, MaxtheKiller_Gun, MaxtheKiller_Gun, hjang128, 27mmueller, andresfrergut, 3490285485, SSC, fomfon191, edugamer323 +100 others
