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…….