Hidden in Plain Sight

I met up with a friend in Tring this morning. Afterwards, walking back to my car, I noticed this alleyway marked as a footpath. I have been up and down this road hundreds of times over the past years and not noticed this alley before! How unobservant is that?
Warning: mind your head!

An extra in a small, wooded area - I am now far more aware of the interesting features in these places. Trees are amazing.