Denehole

A Denehole (alternatively Dene hole or Dene-hole) is an underground structure consisting of a number of small chalk caves entered by a vertical shaft. The name is given to certain caves or excavations in England, which have been popularly supposed to be due to the Danes or some other of the early northern invaders of the country. The common spelli...
Found on http://en.wikipedia.org/wiki/Denehole

denehole

vertical shaft having chambers at the base
Found on http://phrontistery.info/d.html
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