Drifting on the Thames out the front of Tate Modern is a giant cube adorned with (what looks like) illustrations. Atop the cube is a lone figure, still and unmoving as the cube's barge moves slowly with the tide. It's beautiful, and I have no idea why it's there.
I would later hear that the cube has something to do with the 350th anniversary of the Great Fire of London, but I haven't as yet found anything to confirm or deny this. I kind of like how mysterious it is, and that London is a place that can sustain such oddities on a regular basis.
It's probably art though.