found this cave network that is FULL of mineshafts. couldn't get the first cave (well, the first i visited from where i entered the cave lol) in one pic bc it's so big (first two images). Fourth pic is the view of the third pic into the cave – there is a spider jockey spawner very closeby. I've js been wandering around for a few hours lighting things up and going ">:OO THERE'S MORE????" Last two i Just found, prob same giant cave but wouldn't surprise me if they were 2 separate ones, clearly i have not explored it yet (may have to adjust brightness to see).
seed: 915905928654739693, locations in images
edit: info
by beetlespit