Hi. I'm bigbytes and I write about the Washington DC map. Take a look at this animated image which first locates elements in the map, then compares them to features in the GP. Then I overlay the two images:

http://www.geocities.com/jussaymoe/mappyramid2.gif

Note that the relieving stones and chambers in the GP appear to be being depicted in the 1792 map landscape. If you Google John Greaves and "Pyramidographia" you will find copies of his 1640 drawings that he did. Note especially that the relieving stones and chamber are not depicted, as they were not discovered yet. Those were discoveded in 1836!!

bigbytes

Freemasons

"Freemasons"

Masonic and Kaballistic Symbols in the Washington DC Map.

http://www.geocities.com/jussaymoe/dc_symbolism/index.htm

bigbytes