Stob Dearg, part of the Buachaille Etive Mòr range, figures in Bloomer’s Challenge

What makes a munro a munro? Well, the obvious criterion is that it stands at least 3,000ft above a bit of beach in Newlyn.

There is a degree of subjectivity too, as to whether it qualifies as a full-blown munro or just a ‘top’. But one thing is for certain: its status is firmly rooted in the old imperial system of yards, feet and inches.

Consider too, the donald, a lowlier Scottish hill of at least 2,000ft with the totally mixed prominence of 30m. So, why should we venerate a mountain just because it is 914.4m high?

Most walkers, unless they have a particularly touching affinity for old, out-of-date maps, will have been walking for kilometres up and down 10m contour lines since the early 1970s, when metrication hit the world of British cartography.

The Ben Nevis launch, complete with snow

Now, two walkers have decided the future is metric. Jim Bloomer and Roddy Urquhart have produced a hill list for the 21^st century, with no inches and feet, just straightforward metres. Their Prominent Peaks website details 1,564 hills with at least 500m of height and 100m of prominence. The site was launched by the pair on top of Ben Nevis recently.

There is also a new bagger’s list, the Bloomer’s Challenge which, if completed, will take walkers over 158 quality peaks, three of which have 1,000m prominence, and the rest a relative height of 500m.

“These distinctive peaks,” they say, “Are the dominant peaks in their area. The 158 peaks cover all the major upland areas of the UK.”

So unlike the munro list, the Bloomer’s Challenge has hills in the Southern Uplands, Northern Ireland, Wales and England.

The devisers of the list said: “If you attempt Bloomer’s Challenge, you will achieve tremendous coverage of the UK’s hills – from Devon to Sutherland and Fermanagh to Northumberland – and will have visited the highest point of every landmass over 500m.

“While you will not have visited all the highest summits, you will have generally climbed the hills with the most extensive views.”

There is a wealth of information on the website, including downloadable spreadsheets and Google Earth maps.

Jim Bloomer

Jim Bloomer and Roddy Urquhart point out that baggers currently undertaking other lists will probably be tackling Bloomer’s Challenge peaks in among, but say the 500m prominence will ensure they also get to summit some more interesting hills.

Interestingly, only 259 of the current 284 munros feature in the Prominent Peaks list – because of the lack of prominence necessary for status as a munro.

Bloomer and Urquhart are members of the UK Metric Association, which advocates full use of the SI system.