1. Incapable of being ascended
   - unscalable 
2. Incapable of being surmounted or climbed
   - unsurmountable

See also: impassable, unpassable

• Shia Muslim
• Shiah
• Shiah Islam
• shiatsu
• shibah
• shibboleth
• shield
• shield bug
• shield fern
• Shield of David
• shield-shaped
• shielded
• shielder
• shielding
• shieling
• shift
• shift key
• shift register
• shiftable
• shifter
• shiftily
• shiftiness
• shifting
• shiftless
• shiftlessness