That's a buckeye???

Wow.

Equipped with a lightning rod.

Thanks beng!

I suspect that being located in overflow suburbs coming out of Chicago may have something to do with the tree's size, since the temperature likely does not drop quite as low there, I would assume. Very cold freezing temperatures tend to impose a height limit on trees. Yet the tree is also likely to grow taller because it is not farther south and the summer time temperatures are not as hot. Oakbrook appears to be just 25 miles north of this tree's natural range.

I also notice the roots look like they have plenty of room and do not look like they are having to compete with any other significant plants in the area.

A tall tree like that will definitely need a lightning rod in the Midwest.

Wow HUGE buckeye.

Ohio buckeye is the ”in” tree here at the moment. People (finally) realized they can grow well here and now we’re in a fad. I’m ok with this fad.

Thanks, arbordave. I see a tiny piece of that "thing" underneath the tree in your pic, and it looks like it's covered w/bark, so the only guess I have is a VERY eccentric branch of the tree.

Yes, if you traverse the driveway surrounding this tree on street view, you can see the curved branch that forms what Ben perceived as an "eye".