. This is a view of Seneca Stone Mill ruins in Montgomery Co., Md. from inside the structure. Today was very warm and this painting took me a long time to complete. Plein-air painting can be very much like meditation when you sit motionless for so long. The concentration is intense most of the time...at least..for me it is. This old building is very large and fascinating. It was built in the early 1800's. A tree fell nearby while I was painting. Glad it wasn't on top of me.