Since Blizzard's modern "Reforged" version changed how custom maps work, many players use legacy clients:
Visit the Official PlayDota Map Archive (or community mirrors like Epicwar) to download the latest .w3x map file (e.g., DotA v6.85k). Dota 1 Free Download
: You must have the original files for Warcraft III: Reign of Chaos and its expansion The Frozen Throne installed on your PC. Step 2: Download the Dota Map : Dota 1 Free Download