The Cheddar Survey "Therion" 3D file by University of Bristol Spelaeological Society is released under a Creative Commons license.
Creative Commons License

Open Street Map overlay © OpenStreetMap contributors.

Overlay of old Ordnance Survey maps from National Library of Scotland under a Creative Commons Attribution 3.0 Unported Licence. You can also read the full legal code of the licence.

Contains Ordnance Survey data © Crown copyright and database right 2015.

Contains DTM data © Environment Agency copyright and/or database right 2015.