The site of the Boston Massacre, above, just outside the entrance to the building where I work.
From the 11th floor, it looks like a Stonehenge-type primal monument, an extraterrestrial landing spot: a wide circle of well-worn brass, studded with stars, enclosing a rough mosaic of small granite blocks.
Usually people are circulating in loose circles, not sure what they should be looking at.
Here's the backdrop to the whole scene: the old Massachusetts State House.
What does this have to do with Mixed Reality?
Hold on, I'm getting to that.