That's the Big Fat Hole, according to Padraic. Close enough.
The excavators worked all day today and will be back tomorrow. We certainly didn't try to measure it or anything, but we don't think the hole is actually at full depth yet. They've done a great job with carting off the dirt, though, thank goodness. They'll leave enough for the backfilling but take everything else out in a dump truck. So no enormous piles of dirt leftover like we had with the garage project. And to be honest, the first thing I thought when I saw the work they'd done today was how very neat they'd been about it all. Really, not much of the lawn is torn up compared to what I thought would be. So far.
Tomorrow I work from home w/Padraic here with me so we'll be able to watch the progress on Day 2.