At this point, this definitely isn't dull - although I'm probably dull since I keep digging... What I thought was the bottom slab of my supposed antique poor man's cooler sounds hollow and has stone sides that extend below it.

This is a follow-up on this post. I kept digging because I wondered why the brickwork extended so far down for no obvious reason.

Today was a warm day, and the now-exposed frozen ground had thawed enough that I could finally dislodge the rest of the bricks. I found a whole lot more bricks, and some properly ancient wood shoring slats - black and almost completely decomposed, unlike the slats I found above them on Sunday. Half of the bricks and the black wood slats were completely surrounded by thick tree roots, so they've been in the ground at least long enough for that former birch tree to grow 6 inches in diameter.

This is what I dug out today:

I think I got all the bricks out - either whole or as shards I dug out of the tree roots. And so I tried to lift the slab, and... I couldn't because there are solid walls all around below it. This is the top of a stone box. And it sounds hollow when I hit it with a steel bar.

At this point, I'm well below the level of the lake. The water starts pooling at the bottom of the hole when I dig around the box:

I'd say whatever hollow space exists under the slab is probably no more then 4 or 5" above the lake water, which is probably what I'll find when I lift it. Like I said in the other post, the lake used to be lower. But now whatever this mystery space is has probably been underwater for at least 15 years.

I'm gonna have to call a friend or two to deal with this further: whatever is there isn't budging, and I can't dig this far down: I have a disability and I don't have enough balance to stand down there and dig this low down.

So, stay tuned to find out what's hiding in the mystery stone box 🙂