This painting is titled Wivenhoe Park, Essex by John Constable. It was painted in 1816 for Major General Francis Slater Rebow. Can you see anything unusual about the picture? Minnesotastan noticed it.
I first saw this painting about 30 years ago in a print that was on the wall of the office of a colleague of mine at the University of Kentucky. After looking at the painting for a while, I initially concluded that the artist (world famous for his landscape portrayals) must have made an error in depicting the scene. Nobody else seemed interested in the apparent anomaly, and I lost track of the painting (not knowing its title) until I encountered it again this past week.
I invite you to explore the image (it should enlarge to wallpaper size with a click) to see if you find anything that appears internally inconsistent in the content.
Whether you find it or not, you'll be interested in the explanation at TYWKIWDBI. Minnesotastan tells us where the anomaly is, and then looks into the background of how the painting was constructed to reconcile what we see with what Constable had to work with 200 years ago.