Baholin's duct opens and drains its secretion to:

Greater vestibular or Baholin glands are the homologs of the male bulbourethral or Cowper glands. They are in contact with and often overlapped by the posterior ends of the vestibular bulbs. Each gland is connected to the vestibule by an approximately 2-cm long duct. The ducts open in the groove between the labia minora and the hymen-the vestibule-at approximately 5 and 7 o'clock positions. The glands contain columnar cells that secrete clear or whitish mucus with lubricant propeies. Ref: Hoffman B.L., Schorge J.O., Schaffer J.I., Halvorson L.M., Bradshaw K.D., Cunningham F.G., Calver L.E. (2012). Chapter 38. Anatomy. In B.L. Hoffman, J.O. Schorge, J.I. Schaffer, L.M. Halvorson, K.D. Bradshaw, F.G. Cunningham, L.E. Calver (Eds), Williams Gynecology, 2e.