"Walking the Nile", by Levison Wood, is part of today's Amazon UK Kindle Daily Deal at 99p. I watched the TV series of this last year, which was excellent, so I'm very much looking forward to reading the book: a travelogue about (as the title suggests) walking the entire length of the Nile, from its source to the point where it reaches the Mediterranean in Egypt. The author is a former paratrooper who is well known on British TV for his travel documentaries. Always very entertaining.
https://www.amazon.co.uk/gp/product/B00K8WYP6A
Edit: I see that another of his books,
Walking the Himalayas is currently also sale at £2.99. This book apparently won the "2016 Edward Stanford Adventure Travel Book of the Year" award.