and discusses if there is a reason that Orthanc has 27 steps.
Is it because several medieval castles have 27 steps into their towers? or just a coincidence?
includes this factoid:
many medieval stairs were designed with uneven tread depths in order to make it difficult for attackers to rush up the stairs.
the main reason I linked is that this excellent blog was offline for awhile. Martinez has been writing about Tolkien for years, before the blogosphere grew.