Had a bit of a surprise just after noon today; I was in the northern part of the market, near the Elisabeth Bruyere, and spotted a low-flying but sizable (2ft×2ft) quadcopter flying a slow grid over the neighbourhood. It was only about 10 meters up, but there was some kind of payload hanging off the bottom.
Any thoughts on what it might have been? I know that there are a couple of embassies near there, including the US. It's close enough to Parliament that it's probably controlled airspace.