This is a small hole below the track that drops into a 1m deep rift with no draught. The hole would dig but is a "poor site".
Site 2230a is described as "a draughting hole in foot of large depression". Both holes currently have the same GPS.

Reference: anon., 2005b (Easter & summer)
Entrance pictures: yes
Underground picture(s):
Video:
Detailed Survey :
Line survey:
On area survey:
Survex file: