If you look carefully, you'll notice a bird at the very tip-top of the pine tree. What a fine observatory: "Port out, Starboard Home!" eeeeeeeeeeee!
I've included a few other drawings of the garden and a photomontage taken one rainy day last year. I wasn't dressed for the weather and it was miserable. So I decided at the least to trespass a little :-( and take some quick photos of the Pinetum from places the public is not allowed to go.
Here's a link to a short history of the Hunnewell Pinetum (pdf file). There's also a Wikipedia entry.
If you're curious about it and want to sketch there sometime, let me know; I'd love to show it to you!