A concrete base for a machine, most likely an incline winder, as it is directly on and at the head of the trackway route to the lower 1923-4 antenna extension array site. It measures 2.87m long by 2.34m wide and has a depressed impression of a machine base set centrally, being 2.06m long by 0.55m wide.  Two iron bolts of ¾ inch external diameter are embedded vertically, protruding 23cm (9 inches) from within the depressed machine base impression, set 1.98m (78 inches) apart. A further two such bolts are located internally, in a line with the other two and separated from each of them by 0.6m or 23½ inches.

Source: Rowlands, J., ‘Marconi's Carnarvon Station 1912-1939: a journey into early commercial wireless in north Wales’ Second Edition.

RCAHMW, 2023.