I’ve no desire to climb all the Marilyns – UK hills and mountains with a drop of at least 150 metres on all sides, meaning summits of the ilk of Cairn Gorm, Sca Fell and Carnedd Dafydd are excluded. Besides, there’s more than 1500 of them. It is a list for the super-devoted and the ultra-motivated only. Two of the Marilyns are perilous sea stacks located among the isles of the St Kilda archipelago, making the accomplishment of climbing them all a colossal undertaking.

Munro-tagging has a degree of coolness associated with the pursuit. Scotland’s 3000ft mountains are, after all, at times challenging and cruel, but always immensely rewarding. The Marilyns, despite many Munros and numerous other entrants on the more glamorous hill lists of the UK being among their ranks, lack the same prestige. I’m a fine one to talk, however. At least the Marilyns are ‘proper’ hills, unlike some of the obscure molehills I conquered in pursuit of the UK’s historic county tops.

So the odd Marilyn won’t hurt. Botley Hill is my nearest such peak, rising on a ridge of land on London’s southernmost fringe. Being the only Marilyn inside the concrete ring of the M25, the hill has heightened kudos. I found the hill south of Woldingham, set among green and pleasant land punctuated by transmitting paraphernalia, after cycling 15 miles from inner London, most of it, naturally, uphill.

So what of 270-metre Botley Hill? Not a lot, unfortunately. The hill was crowned by a circular water tower, surrounded by three further transmitters. Pretty, this summit is not. Listen hard and the drone of the M25 is just audible. There was no view to the south, trees obscuring the vista. To the north, London nestled in its river-split bowl, the arch of Wembley stadium the most prominent landmark. Still, I had reason to be glad. The sky was blue and cloudless, and I had made it to the zenith of the inner-M25. I could go no higher (until next year that is, when the newly-constructed Shard – and obviously unnatural – will stand 40 metres loftier).