For those having trouble finding it, there is a plateau slightly northwest of Durnholde Keep in Hillsbrad Foothills. At the back of this plateau, where it meets the mountains (the Alterac Mountains, incidentally), you should find a small path leading up into the mountains [77, 19]. This path twists back and forth, goes through a small cave, and then leads to Ravenholdt Manor. There is a chest that will spawn Milton Beats if you open it.
During the Valentine's event quest line before patch 3.3.0, adventurers are led to a valley behind the manor to find Apothecary Staffron Lerent. To reach this valley, first go to the manor then look for a small fighting ring to the right of the manor entrance. Behind that fighting ring is a small mountain pass. Go through that pass and hang a sharp left, and the apothecary will be directly in front of you.[89, 74]