Silva Fil'naveth is a level 65 hippogryph flight master located in Nighthaven in the contested territory of Moonglade. She only provides transport to Darnassus for Alliance Druids.
It is a straight one-way flight which ends at flight master Vesprystus. The player is not able to fly back from any flight master including Vesprystus himself.
Fil'naveth is the opposite of the tauren flight master Bunthen Plainswind, who gives a ride to Thunder Bluff for Horde Druids.
See List of Moonglade NPCs.