Tuesday 3 July 2012 1.15am
no no native American Burial grounds but ALOT of Plague Pits and Paupers graves! I know there are alot of Underground Sidings etc between Borough and The Elephant.
We too have it just off Southwark bridge rd infact we have just had one at 1.05am this mornin that reminded me of your posting. I would describe it as a prolonged shudder. 10-15 seconds ish.
there is also this