hidden

not accessible to view

• “concealed (or hidden) damage”
• “in stormy weather the stars are out of sight”

covered from view

• “her face buried (or hidden) in her hands”
• “a secret buried deep within herself”

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”

difficult to find

• “hidden valleys”
• “a hidden cave”
• “an obscure retreat”