A cul-de-sac is a passage with access only at one end. It is a dead-end street or alley that is closed off at one end, usually by a wall or fence. An ADIT is an entrance to a mine or tunnel, typically at the side of a hill. It is a horizontal or nearly horizontal passage from the surface by which a mine is entered and dewatered. Both cul-de-sacs and adits are passages with access only at one end.