This guide does not purport to be exhaustive! To create a series of rambles which visited every folly in northern England would result in a ridiculously large volume. I have had to leave many follies out, so many in fact, that I felt obliged to suggest further options for the wood-be-folly hunter. I have done this by the creation of a gazetteer. Not all of the follies mentioned there have been personally visited, and there is scope to make your own explorations and discoveries. My reasons for omissions have been various. Some are sited in predominantly urban areas which offer little scope for ramblers, some are on private property, and may (or may not) be accessible to the public on payment of an appropriate entrance fee.
Some follies are dangerous (Mowbray Point at Hackfall is a good example). Rusty nails in fallen beams can pierce even the stoutest boot, and the dangers of rotten floors and crumbling masonry should be palpably and appallingly obvious! By all means explore, but if you must err, err on the side of safety. Broken in boots are acceptable, broken in heads are not!
Writing the follies books was for myself and my family something of an adventure. Hopefully, using the information contained herein you will be able to continue from where I left off. I will detain you no longer. The vast and varied landscape of Englands largest county awaits!