Across the river and into the trees
Looking down into the valley of the Afon Gwaun at this point there's little to be seen apart from trees and undergrowth and glimpses of reflected light from the river. The sound of the running water fills the ear. There are no paths through these silent woods any more but 70 odd years ago it was different. They harboured a secret that few people knew, even then. Somewhere on the other side of the river here was the HQ of the local Auxiliary Unit.
In 1940 Britain feared the real possibility of German invasion, and while many able-bodied non-combatants had already been conscripted into the Home Guard for fire-watching duties and the like, another, more clandestine network of civilians was being mobilised in each locality, tasked with the duty of undercover operations in the case of enemy occupation. They were all country dwellers - land-owners, farmers, fishers, hedgers, gamekeepers, even poachers - with an intimate knowledge of their own area, familiar with the lie of the land and how to live off it, how to move around undetected, to melt into the scenery and to cover their tracks. If necessary they would be required to fend for themselves unsupported. Each cell was provided with a sub-machine gun and a high velocity rifle, each man was issued with a pistol, a dagger and a heavy truncheon. Their job, if Britain was invaded, would be to support the regular army via acts of sabotage, ambushes, booby traps and fast getaways but each individual would be required to act alone - for as long as he survived..
Each cell constructed its own HQ with materials supplied by the army. These concealed underground bunkers comprised very basic living space for a 6-man patrol together with food, water, weapons and ammunition, plus equipment for sabotage viz. grenades, gelignite, sticky bombs and detonators. The construction of the bunkers and subsequent meetings for training and planning all took place secretly at night, by day the recruits carried on with their normal jobs, even wives and families were unaware. (Needless to say all this nocturnal subterfuge led to much misapprehension and it's tempting to imagine that the scheme provided the sort of recreational pastime that the Men's Shed scheme offers today.) Nevertheless the Auxiliary Units remained in place until disbanded in 1944 after the tide of war had turned in the Allies' favour.
There's no way of knowing where the local bunker was exactly. It must have long sunk back into the earth that held it, roots have invaded the site and the men who manned it are long departed. My favourite local historian whose information I have drawn upon here has sadly gone too - he was a boy at the time and may well have sussed out the bunker's location. The members of the Auxiliary Units were never publicly revealed and remembrance day does not include them. Fortunately they were not called upon to risk their lives but the novel Resistance by Owen Sheers supposes an alternative scenario in which a German occupation of the country means that another Welsh valley's menfolk disappear overnight to do their duty as undercover operators.
Online see here, here, and here.