At work, groups of us have been teaching high school classes about archives, why they're not as geeky as you'd think (if you'd ever thought about archives), and what it's like to be archivists. For the first class, each of us brought in something archival of our own as an example. I ended up bringing in one of the notebooks I use to organize information about my knitting (look! It does relate to knitting after all!), because I figured it was best to get have my knitting-nerdiness out in the open right away.
But I thought a lot about bringing in something about my paternal grandparents. The main thing I associate with them is their garden--they retired to Spartanburg, SC and over time, bought up quite a bit of land. There were houses around the edge (which they fixed up and rented out), but most of it was being used as an unofficial dump. So they cleaned it up (I want to say they pulled out abandoned cars and refrigerators, as well as general trash, but that may be my imagination), and turned it into a beautiful garden, with flowers, trees, ponds, streams, paths and ducks (my sisters and I loved feeding the ducklings every spring).
As they got older and started to think about how it would be cared for after they died, they gave it to the city as a municipal park. One of the lots on the perimeter became a continuing care facility, where they both lived at the end of their lives. I haven't been there in years (and honestly, it's a little weird to think of so many people visiting what I thought of as my grandparents' backyard, even if that's what they wanted), but it's flourishing, with a website and everything.
All this is a very long way of getting around to what I meant to write at first... that even though the garden is what I think of, it was actually towards the end of a long list of contributions, most of which I don't think of because I didn't experience them directly. There's a book about my grandfather, which I've read, but I'm still surprised by where he turns up. Such as with Martin Luther King. (My grandpa is the one with his elbow on the table.)