hidden

Adjective

• difficult to find
  • hidden valleys
    
  • a hidden cave
    
  • an obscure retreat
    

• designed to elude detection
  • a hidden room or place of concealment such as a priest hole
    
  • a secret passage
    
  • the secret compartment in the desk
    

• not accessible to view
  • concealed (or hidden) damage
    
  • in stormy weather the stars are out of sight
    

Related words

• Synonyms: 
  obscure , secret , concealed , out of sight