Eduardo's stone problem

So we managed to get the large stone block out from underneath the window. We will use this stone to make a window seat. A good idea I think to keep it pretty much where it has laid for the last 800 years plus! The bad news was that underneath the block is another huge piece of rock.

It is not a carved block but just a large rock, probably part of lower foundations from whatever stood here years ago. I am starting to worry that there is a big wall foundation lying exactly where we want to put the drainage pipes in.....