The Sun

The first time I saw this was in 2011, while I was running in the Redlegs 5K.  I went back last summer, having forgotten where exactly it was, and missed it each time I passed by.

And I think sometimes some signs disappear unless the sun is hitting them just right.

 

Update 4-27-13:

I had a dream last night where I ran a 5K, the first in about a year.  And I was doing fine, except when I stopped to take pictures of ghost signs.

 

I think I have a problem.