The four shafts coming out of the Queen's and King's Chambers have been a popular mystery. What was their purpose? Are they 'star shafts'? Do they have a special geometry? You might like to look into the writings of Rudolf Gantenbrink. (Google him.) There has been a lot of mystery surrounding the two blockages in the upper southern shaft, and there have been several TV shows on these shafts, so you may even be able to get some audiovisual material together from your local library.