The dungeon...a.k.a. "the crawlspace" is a stunted floor underneath the main floor, leaving just enough room to belly crawl around and check pipes and wires. Observe...
It used to be a dirt floor down there, but Mark has laid a 15 mil layer of plastic, and now we are working to seal it around the edges. Ultimately, it should be vapor-tight. Now here is Mark working diligently on...something. Actually, he is posing per my request, showing me how to caulk the plastic lining to the wall, which is my job for the day. This is the tiniest corner, but there are fewer ducts to deal with.
Not the most inviting space in our new home...yes, it's a dungeon, but it's OUR dungeon!