chim·ney
 /ˈʧımni/  noun  ,  pl   -neys [  count  ]
  1 : a part of a building through which smoke rises into the outside air; especially : the part that sticks up above the roof — see also smoke like a chimney at smoke, 2
  2 : a tall narrow opening through a large piece of rock (such as a cliff) that can be used for climbing the rock