Monument/Mausoleum

I've often wondered what the monument or mausoleum is by the barracks as well near Woolwich that you drive past by the side of the road. It looks to be all chained up and I do often mean to park the car up and try and have a nosey but it looks a bit rough around there so I've never bothered. It is, or was, stunning whatever it is and looks like it has the remains of an old drinking fountain in it. Anyway I have just mid sentance thought to google it and it is the old St George's Chapel that was part of Woolwich Barracks and there are plans to try and restore it, in time for the Olympics (Which I am very very much in favour of)!