This mound of earth is generally called the Castle by the peasantry, among whom some singular tales are current respecting the cause of its formation.
One of these is a vague story of a certain Queen, who having made a wager with the King, that she could encamp a large army of men within a bull’s hide, ordered the bull’s hide to be cut into strings, and the greatest possible circle to be encompassed therewith: this was done accordingly, and the encampment made upon this spot.
From p29 of ‘The Beauties of England and Wales’ by John Britton, and others (1801).
This relates to Totternhoe Knolls, an 11th century motte and bailey castle built on the site of a prehistoric enclosure, not the site of Maiden Bower.
The quote is from John Housemans 'Tour of England'.
Ooh tut tut, well now I look at it that's partly John Britton's mistake and partly mine - he actually connects it with Arbury Banks, so god knows where I've got the information from, bad reading maybe, maybe you can't believe a word I say. I'd get it moved to Arbury Banks but if that's not right either... (I say right. But you know what I mean).
archive.org/stream/beautiesengland00braygoog#page/n46/mode/2up
Your John Houseman was a bit earlier? I've seen his Nottinghamshire notes in the 'Gentleman's Magazine' - is that where the Bedfordshire bit comes from too?
Yes, I noticed that too. Houseman specifically mentions travelling a mile outside Dunstable before going on to write the bit quoted in your original post, so I'd say the mistake is almost certainly Brittons.
And yes, Gentlemans magazine.