Sandstone, shadows, and shoes
Spot the invisible caller in large.
I found these shoes slightly surprising; I'm not sure why, but they grabbed me...
I was going to blip the mallard that snuck up on me, the dangerous duo, or Isis Lock, but in the end it was the shoes (and their explanation, whatever it may have been) that won.
I've uploaded other shots from my amble along Oxford Canal to Flickr (right from here).