Anyone who has walked along the path through Bee Wood below Froggatt Edge must have momentarily paused at the strange tomb like structures on the edge of the path and wondered what they were. I certainly have done, and unable to find any information about them in my Peak District books or on the internet, I contacted the National Trust who manage the woodland, and I am delighted to report that I now have the answer!
Apparently they are part of a water company piping system along the path which is known locally as the ‘pipe track’. The rectangular gritstone structures cover vent and access holes to the ‘cut and cover’ pipe. The pipe was apparently a dug ditch that was covered in an arch of bricks then covered back over.
Peak Walking Adventures Blog 
Thanks for doing this research. I’ve walked past these structures and drew the conclusion that they were something to do with water supply; but I couldn’t work out exactly from where. I never thought they looked like tombs though, more like plinths that grandiose statues would be placed on.
Thanks Lee. I like your interpretation of what they resemble much better than my own!
Thanks for this information, we too have wondered what they were. We noticed a metal label saying WSG 002 050 on one but that didn’t help!