Source : Webster's Revised Unabridged Dictionary (1913)

Inaccessible \In`ac*cess"i*ble\, a. [L. inaccessibilis: cf. F.
   inaccessible. See {In-} not, and {Accessible}.]
   Not accessible; not to be reached, obtained, or approached;
   as, an inaccessible rock, fortress, document, prince, etc. --
   {In`ac*cess"i*ble*ness}, n. -- {In`ac*cess"i*bly}, adv.

Source : WordNet®

inaccessibly
     adv : in an inaccessible manner; "located inaccessibly on the top
           of a mountain"