After spending rather large amount of time down in the abandoned mines under
my place, I have come to the conclusion that the thing never ends. So far, I've
found total of 15-18 chests, countless number of spider spawners, few small
cave systems, yet the place just keeps on going. I dig out some gravel and
uncover another shaft, follow it and it branches to 2 more which branches to
2 more and on and on.
To put it in another perspective: I've so far covered 3-4 times the area I covered in
the biggest buried ruins system I found in YogBox.