Here's where we last left Under Glasslake, stretching 20 blocks North of the end of the Cathedral. You've seen this pic before in the last postcards episode.
After quite a lot of partially-successful TNT and enchanted diamond pick, it looked like this (my trusty steed Super Lala Coo Coo standing by):
And then with a concerted effort this afternoon:
Done! Not sure what the next project is going to be. I'll probably leave it for a bit and come back later. :)