Andrew Mok and Simon Whitmarsh are both keen walkers, covering over 2000km a year. They have walked extensively in Britain, doing (at least part) of all the major trails, have hiked across England twice, and have walked in most countries in Europe. More recently their addiction to mountains has increased, with treks in the US (including many parts of the Appalachian trail), Australia, New Zealand, Andrew's native Hong Kong, and Nepal (Everest Base Camp).

They are both doctors, a General Practitioner and a Consultant Paediatrician, who decided to write this book after being delighted and astounded by the walking opportunities of Portugal. When not travelling, they enjoy finding new routes near their village in Snowdonia.