Cadair Idris is a wonderful mountain. A true spectacle comprising rugged ridges and steep ascents, with a shimmering glacial lake at its heart. A walk here is an unforgettable experience. Or so I’ve been told. I’ve never actually been there.

Some months had passed since my previous leg of the Two Moors Way had ended in the dark. Since then a new job had lessened the opportunity for mid-week days out and a plan to beat the seasonal heat had been curtailed at short notice due to illness. So the troops (or three of us at least) reconvened on a June weekend not far shy of the longest day.

Nick Ackfield works with National Park Authorities, tourism boards and local councils in the UK to help them improve their visitors’ experience with what3words. He explains how the system, which has given every 3 metre square in the world a unique combination of three words and is available via a free app and online map...