They are found all across the country, weaving and intersecting in what often appear to be completely unplanned patterns. Some are ancient, some more recent; some have names, others are anonymous. Some are concrete highways, others are barely there at all.

As the worst of the Covid pandemic draws to a close, what better time to encourage people to get out into the countryside for a walk? As a resident of northwest London, I have a special advantage in doing that - an urban rail network that reaches right into the heart of the countryside.

Largely neglected by walkers because of its proximity to National Parks both north and south, the scenery of the northern part of the Elenydd, the Cambrian Mountains of mid-Wales, is nevertheless wild and stunning.