High above the rest of the Downs, nestled atop the enormous tree, is a structure that appears to be a residence.
On top of the residence is an observatory.
One can only imagine the effect of this structure on Miss Heliosense's more modestly-sized observatory nearby.
On the subject of trees in the Downs, I discovered that one of my own trees was actually sitting on Mr. Mannonen's property. (Actually, I assume he discovered this after making changes on his land, and finding that he was still using a number of prims that, ah, turned out to be mine.) I was puzzled, because I felt certain that I had placed the tree squarely on my side of the property line. I tried again, making certain through various surveying tools that the tree lay on my land. I looked at the number of prims on my land - the figure had not changed. I inspected those on Mr. Mannonen's land - the figure rose. Most odd.