Cambrian Patrol was first set up more than 40 years ago, by a group of Welsh Territorial Army soldiers who designed the training event to feature long distance marching over the Cambrian Mountains culminating in a shooting match on the Sennybridge training area.
Castell Du, also known as Sennybridge Castle or Castell Rhyd-y-Briw, is located approximately eight miles west of Brecon in Powys, Wales, and is believed to be the work of Llywelyn ap Gruffudd, Prince of Wales.