1861 97/1 The Ring Ditch of Martin Mere.
1936 1 8 In the following pages some account is given of the investigation of barrows and ring-ditches in the Oxford area.
2000 E. Hunt et al. 438/1 A turning..leads you to a large sign describing the circular Velata Mound Fortress, a ring ditch fortification of a type widely found throughout Tonga, Fiji and Samoa.