To experience the real freedom of the mountains, you've just got to break out of a prison camp to get to them, says Ronald Turnbull, of this enduring account of DIY mountaineering from World War Two. With lockdown still in progress we can all empathise, but don't be tempted to emulate Benuzzi's feat!

In 1935 Mussolini's Italy, playing colonial catch-up, overran Ethiopia. In 1941, with the outbreak of World War Two, the British overran the Italians. And colonial administrator Felice Benuzzi found himself interned in Prisoner-of-War Camp 354, in the middle of Kenya, two minutes' walk from the Equator. With, added to the boredom and misery of imprisonment, one especially cruel twist.

Framed in the barbed wire, 20 miles away and 3500m above, Africa's second highest hill, Mount Kenya. Looking 'like Monte Viso, but so much more impressive'.

And so was born one of the two great mountaineering masterpieces of the prison camp system (the other being WH Murray's Mountaineering in Scotland, famously written on bog paper under the eye of the Gestapo). One of the two great 'OMG did that really happen?' mountain stories (the other being of course Touching the Void). Felice Benuzzi, with two companions, broke out of PoW Camp 354. They climbed Mount Kenya. And then they broke back in again.

Before the breakout, they spent eight months preparing equipment. Ice axes converted out of stolen hammers. Hand-crafted crampons. A bed-net was painstakingly unknotted to make a totally inadequate sisal climbing rope. And then they had to find out about the mountain. They had just enough Swahili to ask an old local who was illegally trading bananas for camp cigarettes. An old local who didn't know anything at all about getting up Mount Kenya.

But then they got lucky. A tin of compressed beef, Kenylon brand, had on its label the unseen eastern face of the mountain...

Half the book consists of just reaching the base of the climbing; nine days of variously unpleasant vegetation bands nowadays crossed by four-wheel-drive jeep. There was dense jungle, inhabited by rhino, leopard and elephant, which they clambered through following the bed of a stream; above the jungle, the bamboo thickets; above the bamboo, the dreadful tussock grass.

The climbing on Batian, the main summit, is graded Hard Severe (Alpine D) by the normal route. But they don't find the normal route. Instead they attempt the unclimbed northwest ridge – a line that had been rejected as hopeless by Shipton and Tilman 13 years before. Do they get up it? Let's not spoil the story...

And then back down again, through the various vegetation zones. Their packs are much lighter now, without the added weight of the camp-made Italian flag and climbing gear. Lighter also because of carrying not a scrap of food, for the three days of the descent. They break back into the camp, enjoy a large meal and a good night's sleep, and present themselves to the Camp Commandant next morning. Who, in recognition of their sporting achievement, commutes the expected 28 days in the cells down to a week.

The book's writing style is understated and mildly self-mocking, in a way we might think of as peculiarly British, although of course it isn't. It is also peculiarly poetic; every detail of the trip, and especially the amazing landscapes of the upper mountain, brought vividly back to life during the following years of imprisonment. I looked for the name of the sensitive translator, who also imposed the ironic title (the Italian Fuga sul Kenya just means 'escape to'). There wasn't one. Benuzzi, with time on his hands and perhaps in tribute to the mountaineering history of his captors, wrote the book twice, first in Italian and then in English.

The Maclehose Press edition of 2015 reproduces the cover from the first American edition – a three-colour lithograph that only slightly exaggerates the drama of the climb. More importantly, it retrieves, in frustratingly small format, 22 of the other-worldly watercolour and pencil sketches made by Benuzzi on the expedition.

To experience the real freedom of the mountains – just break out of a prison camp to get to them.