Full detail of this land feature defies explanation in a couple of lines; and is
beyond this casual blogger.
It is believed that between 13000 and 10000 years ago vast icy reservoirs flooded
the Glen Roy valley. A mass of deep ice occupied the larger Glen Spean valley to
the south. (The present River Roy being a tributary of the River Spean). The ice
to the south effectively dammed and retained the loch and it is understood this water
at one stage would have spilled seaward to the north over the present watershed to
the Spey Valley. There are three stages of the retaining ice suddenly relenting over
the period resulting in three distinct shore lines being cast on to the Glen Roy
mountain side. Still plainly visible they are known as the Parallel Roads. Roy is
simply a corruption of the Gaelic “Ruadh” meaning red. Glen Roy, its mountains, and
upper reaches are worthy of further exploration where fine vantage points can be
reached to view this natural spectacle. Despite this a very cheap - in terms of effort
- but excellent road side view is gained from a visitor car park. There is a sign
board and cairn here offering clear graphics of the process as it unfolded.
The aptness of “Red Valley” name is evident in the right light and bizarrely three
of the glens four Corbetts are actually named “Carn Dearg” or Red Hill. (Dearg pronounced
Jerrack also meaning red) Charles Darwin, following a visit in 1838, famously misinterpreted
the origins of the parallel roads committing to text that the lines were effectively
old sea shores. He conceded many years later and shortly before his death that the
Louis Agassiz theory was the more likely explanation.