some prelim stufff
https://www.tsgcaving.co.uk/content/Trip-Reports/maury-sough-alan-brentnall
http://www.winstercavers.org.uk/PhotoGallery.aspx?GalleryID=8
https://historicengland.org.uk/listing/the-list/list-entry/1412310
Horizontal distance is over 600m