This cache will take you up (or down) the valley of the River
North Esk in Midlothian between Penicuik and Loanhead.
While I will always deeply regret the circumstances that brought
me to live in this part of the world, there are many compensations.
Running in this valley with the deer, kingfisher and herons is
one.
You can park near Polton on the south eastern side of the bridge
(N55 52.272 W003 08.323) on the side road between Bonnyrigg
and Loanhead. Take care because the road is narrow, winding and
steep both down and up into the valley. It is also often used by
riders from the nearby stables. Think horse and pass wide and slow
if you meet any. But I prefer to start from the Kevock road, just
off the A768 between Loanhead and Lasswade. There is a small path
down to the river starting at about N 55 52.717 W 003
07.605. It’s a longer (and muddier!) walk or run this way, but
worth it. It’s also convenient for the 31 Bus from Edinburgh and
the Penicuik bus that runs through Loanhead.
When you get to the spot, you are standing on a high bluff
called the Maiden Castle, round which the river makes a deep, deep
curve actually turning back on its course for part of the way. Why?
The secret is in the geological history – which also explains the
deep gorge of Roslin Glen further upstream. Geologists now think of
the end of the last glacial period as being very sudden. The
glaciers melted in a short space of time and huge quantities of
melt water ran off as raging, torrential and destructive rivers.
The now placid North Esk carved itself a deep cleft through the
resistant sandstones around Roslin, then spilled out in a much
wider course into the softer rocks below. And in doing so, the
water slowed and deposited huge quantities of glacial drift, sands
and gravels that are piled up under you forming a barrier that the
more modest river we now have cannot penetrate but must negotiate
with a long, slow double ogive. Judging by the contours, there was
probably a large lake here before the aftermath of the post-glacial
flood subsided.
Despite feeling solid, the pile of sand and gravel you are
standing on is not well consolidated. And to make matters worse,
springs leak water through the layers, lubricating the whole lot
and making landslips inevitable. To help things along, the area is
subject to regular minor earth tremors. A major slip occurred in
1979 when the Seafield Mill (now a cleared site in the foreground)
below the bluff was occupied. The noise of the mudslide was said to
be “like a number of lorries driving through your living room”.
But the main reason for bringing you here is not to deliver a
geology lesson. It’s to share the view. So move away from the cache
site and closer to the edge of the bluff. Choose a clear day for
this one, and the view north east up through Midlothian, East
Lothian and out to the Forth is well worth the walk. A fresh, green
and wooded landscape just minutes from Edinburgh. Lifts the
spirits, doesn’t it?
And if you fancy a little more of the river’s company, why not
head on upstream and do “Priors of Sion” which will take you into
the cleft of Roslin Glen and the mystery of the Grail…….