Marilyn (Gaping Gill)


Issued: 1 November 2018

Towards the end of 2017 we were informed of a substantial collapse of the traverse shelf that leads around the top of Mud Hall. The traverse shelf has since been partially restored with an in-situ rope demonstrating the route. All cavers should however be aware that the area is still likely to be loose and may move further, and the shelf is very exposed. Go carefully, inspecting the route as you proceed and take sensible precautions. The rope and any anchors on this traverse are not CNCC endorsed, and we have had some feedback which draws the integrity of their anchorage into question.

Update January 2020: There has been a further collapse of glacial mud onto the Mud Hall traverse, partially blocking the route. Work is planned for Spring to restore the path, but until then part of the traverse is very hazardous indeed. This second collapse demonstrates the need for continued care when traversing around the top of Mud Hall.



Access to this cave is available to everyone all year round, but must be booked prior to your trip to satisfy the landowner’s requirements for managed access (and out of courtesy to other cavers too). One booking may be made per cave entrance per day. The CNCC has created a simple online booking system to allow individuals to book access to this (and other) caves using an intuitive calendar-based approach.

Book Marilyn

Note: First time users will need to register before being able to log into the system. The process should be self-explanatory but if you have any questions please email our system administrator via the address below.

Bookings made via the online system are live immediately.

Anyone wishing to book access without using the online system can do so by emailing the system administrator. Please include details of which cave you would like to book and what date:

Please note that if you are arranging your booking by email, rather than via the online system, you MUST wait for confirmation from the system administrator that your chosen date is available and the booking has been finalised BEFORE visiting the cave. Please allow two weeks’ notice in the eventuality the administrator is on holiday.

This cave is on access land. Click here for more information.


Twice per year access to Marilyn (and other caves in the Gaping Gill system) are controlled by either Bradford Pothole Club or Craven Pothole Club for their annual winch meet. Booking is not possible during the following dates:

  • Sat 14 May - Sat 4 June 2022 (Bradford Pothole Club)
  • If you are a non-caver looking for information about the Gaping Gill winch. Please see the Bradford Pothole Club website (May meet) or Craven Pothole Club website (August meet).


    NGR: SD 75235 72450

    Lat/long: 54.1472740379531,-2.38063084035976

    Locate on Cave Map

    Please note that grid references are correct to the best of our knowledge however are often taken from old books so they may not be absolutely accurate and are shown simply as a guide.

    What 3 words: blotches.tuxedos.vehicle

    Entrance Photos



    Marilyn is equipped with Eco 'P' resin anchors within the BCA Anchor Scheme.

    Prototype PECO anchors awaiting decommissioning and replacement.

    Rigging Topos and Descriptions


    No surveys have been added for this cave yet.

    Last updated: 30 Oct 2018

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