From WoWWiki

Mystral Lake is located in south-central Ashenvale, just south of Silverwind Refuge and east of the Talondeep Path. It is the largest lake in the forest, and subsequently often visited by both Horde and Alliance characters for various reasons. The water elementals of Mystral Lake pose a significant threat to lower level players.

Subzones of Ashenvale

Astranaar • Bathran's Haunt • Bloodtooth Camp • Bough Shadow • Demon Fall Canyon • Demon Fall Ridge • The Dor'Danil Barrow Den • Falfarren River • Fallen Sky Lake • Felfire Hill • Fire Scar Shrine • Forest Song • Greenpaw Village • The Howling Vale • Iris Lake • Kargathia Keep • Lake Falathim • Maestra's Post • Moonwell • Mor'shan Rampart • Mystral Lake • Night Run • Nightsong Woods • Raynewood Retreat • The Ruins of Ordil'Aran • The Ruins of Stardust • Satyrnaar • The Shady Nook • The Shrine of Aessina • Silverwind Refuge • Silverwing Grove • Silverwing Outpost • Southfury River • Splintertree Post • The Talondeep Path • Thistlefur Hold • Thistlefur Village • Warsong Labor Camp • Warsong Lumber Camp • Xavian • Zoram'gar Outpost • The Zoram Strand