I was working in an office in London and sat across from me was a work colleague, to my right, his left, there was a large open space of window that allowed a view across the adjacent building and up to the sky. I saw something black and flapping large wings in a more bat like way than say a bird, and this creature was big. I got my coilleagues attention and didn't say anything, just inclined my head in the direction of what looked much like a dragon! My colleague looked, and looked, and we both watched it fly across and up into the sky from one side of the buildings. he then looked at me and just sort of shrugged but we both smiled and have never said a word about it. But i have to say, i really do think it was a dragon.