Williamson Tunnels Heritage Centre
- Visitor information. Includes news, and details of their education programmes, the Tunnels Bar venue, and how you can help.
- http://www.williamsontunnels.co.uk/

Friends of Williamson's Tunnels
- Information on the hidden labyrinth and Joseph Williamson, including a virtual tour, videos, articles, and how you can get involved.
- http://www.williamsontunnels.com/

The Joseph Williamson Society
- Charity working to restore and conserve Williamson's network of tunnels, and inform the public about his works. Information about the man, the tunnels, and the society's work to open a visitor centre.
- http://tunnels.www8.50megs.com/tunnels/