Creative ideas for old windows?

In preparation for our new windows in our fireplace & hot tub suites at our bed & breakfast, we're looking for ideas to put these old windows to work!
Can they be transformed into unique Michigan themed artworks? Could they be cold frames for growing herbs & veggies? Should we paint the frames and hang them up with dry erase as whiteboards? These are some of the great ideas we've received on our Facebook & Instagram posts, but we'd love to hear YOUR ideas! Please drop them in the comments!