This is an image and video from from activity I saw taking place at Potter's Fields Park, in London by Tower Bridge (UK) today.
What is it? We just don't know what yet and Trend Hunter is always first to report all things cooooool.
Lots of UK Media down there too today (including London SE1, who took some of these photos). I will update when we know what's going on:
Post comments if you find out first :-