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

See also: impassable, unpassable

• vulcanicity
• vulcanisation
• vulcanise
• vulcanised
• vulcaniser
• vulcanite
• vulcanization
• vulcanize
• vulcanized
• vulcanized fiber
• vulcanized fibre
• vulcanizer
• vulcanology
• vulgar
• vulgar fraction
• Vulgar Latin
• vulgarian
• vulgarisation
• vulgarise
• vulgariser
• vulgarism
• vulgarity
• vulgarization
• vulgarize
• vulgarizer