The remnants of a collapsed sea wall, about 40 metres long and dating back to 1927, were discovered by a passer-by on Fish Hoek Beach on Monday.
The find resembles a forgotten railway track, but is, in fact, the spine of the wall which was made of old railway lines and sleepers firmly bolted together.
According to the Story of Fish Hoek, by Malcolm Cobern, representatives of the Board and the Railway met in November 1927 and decided that a retaining wall of about 4 feet, (1.2 metres) high should be built along the seafront to prevent water from flowing into Fish Hoek.
By September 1928, the Railway had approved a palisade of 510 feet, (155 metres) at an estimated cost of £200 and it was completed in December 1928.
According to Mr Cobern, the wall stretched from just opposite the level crossing and eventually ran the entire length of the beach, up to as far as the Silvermine Stream.
And Fish Hoek Valley Museum volunteer Brian Martin, on Monday, plotted the position of the railway lines – which were the spine of the wall – on 1945 aerial photography and concluded that they were remnants of the old sea wall that had fallen over.