Ms Hatfield walked her first Marilyn in 1972 Ms Hatfield, 58, who worked as a science teacher for many years before moving into medical sales, said she was “absolutely over the moon” to have finished the challenge. Ms Hatfield estimates she has climbed about 243,000m to achieve her goal – the equivalent of climbing Everest from sea level 28 times – covering about 5,370km as well.She said: “The list is great because it covers the whole of the UK, with hills of all sizes, and a huge range of character. It’s a massive list too, but not so big as to be unachievable.”The term Marilyn is a play on Munro – the name for mountains in Scotland that are at least 3,000ft (914.4m) high. A map showing the location of ‘Marilyn’ hills across the UKCredit:Wikimedia There are 1,556 Marilyns across the UK, though most of them are in Scotland A science teacher gave up her job to become the first woman to conquer all of the UK’s 1,556 ‘Marilyns’ – hills with a drop of at least 150m on all sides.Jenny Hatfield, from Cumbria, completed her final Marilyn on Sunday, ascending the 632m Cruinn a’Bheinn, near Ben Lomond, in Scotland.She reached the summit with her partner, Rick Salter, who becomes the ninth man to complete the list, and the couple celebrated with a glass of champagne. The list is great because it covers the whole of the UK, with hills of all sizes, and a huge range of characterJenny Hatfield She told BBC Radio: “It just feels amazing to have that huge list of hills complete.“In the last year, myself and my partner Rick Salter have actually managed to climb 500 of them, so that’s been a huge ongoing every day commitment.”Ms Hatfield walked her first Marilyn, the 950m Helvellyn, in the Lake District, in 1972 while on a youth hostelling trip with her sister. But it wasn’t until 15 years ago that she bought the book The Relative Hills of Britain by hillwalker Alan Dawson, which lists the 1,556 Marilyns across the UK.Over the last ten years, Jenny has climbed many of the Marilyns with her partner Rick, saying the pursuit became a “common interest” for the pair.But she says it was only in October last year, when she climbed the St Kilda sea stacks, Stac Lee and Stan an Armin, that she first saw the opportunity to become the first woman to complete the list. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.