Hidden away on Birkdale Common at the top of Swaledale,
Birkdale Tarn is a magical place; quiet and peaceful and teaming with wildlife.
It is as if we have a secret piece of the Lake District right on our doorstep.
The water level is uncannily low......
and Chris can't remember ever seeing the rocky lake bed exposed like this.
Further round the tarn a black peaty beach.
The southern edge of the tarn is completely walled to hold in the water ....
with a second broad retaining wall built with enormous stone like a mini Hadrian's Wall.
Its an impressive piece of construction which makes you wonder who built it and how hard the men must have laboured, without the help of machinery, to achieve a structure that contains and constrains millions of gallons of water.
A beautiful place to be on a beautiful evening.