A Hump is a hill of any height in Britain or the Isle of Man that has a drop of at least 100 metres on all sides. There were 2984 Humps at the end of 2015.
The list of Humps was first published by Mark Jackson in the book More Relative Hills of Britain, tabulated by David Stone and available via Lulu.com from 2010. As well as doing significant original research, Mark drew on the work of several people including Alan Dawson, Eric Yeaman, Clem Clements, Rob Woodall, Bernie Hughes and Pete Ridges, as acknowledged in the book.
All Marilyns have over 150m drop and so are by definition Humps, but almost half the Humps are not Marilyns. More information about Humps is available in these sources:
As yet no-one has climbed all the Humps, though Ken Whyte has climbed all except eight. The most difficult Hump is thought to be the Old Man of Hoy, though it has had many ascents. There is no record of anyone having climbed Lianamuil or Arnamuil, two sea stacks off the west coast of Mingulay.