The Plains of Snow are a location, somewhere on Azeroth. This arctic land is starkly beautiful, but merciless as well. Its unlikely anything could survive the brutal weather without a thick coat of fur—or the aid of magic.
The World of Warcraft alpha back in 2003 contained a snowy map in the game files which later in development was changed into Azshara Crater. The main body of the map housed a subzone "Plains of Snow" and contained a horde and an alliance side. This could have been one of the first functional battlegrounds since each side had a meeting stone, which in alpha were known as "Binding Stones" - the first iteration of spirit healers for players to revive at. The map had only a handful of assets placed on it and was rather small, it was made mainly with Ironforge tilesets.