Ben Nevis the summit only to find "fragments of earthen and glass ware, chicken bones, corks, and bits of paper". It was not until 1847 that Ben Nevis was confirmed by the Ordnance Survey as the highest mountain in Britain and Ireland, ahead of its rival Ben Macdhui. The summit observatory was built in the summer of 1883, and would remain in operation for 21 years. The first path to the summit was built at the same time as the observatory and was designed to allow ponies to carry up supplies, with a maximum gradient of one in five. The opening of
Lists of mountains and hills in the British Isles was coined as an ironic contrast to the designation "Munro", which is homophonous with "(Marilyn) Monroe". The Marilyns are one of the most popular lists for peak baggers. The Marilyns were expanded in 2007 by the HuMPs (Hundred and upwards Metre Prominence) which reduces the prominence requirement to . Therefore, all British Isles Marilyns are British Isles HuMPS (but not vice versa). The list was compiled by Mark Jackson from a number of sources and published online in 2010 in "More Relative Hills of Britain". There are 2,986 HuMPs in the British Isles: 2,168 in Scotland, 833 in Ireland, 444