It wasn’t quite as thrilling/perilous as a D&D dungeon crawl, but we did walk through the steam tunnels beneath campus, and survived. I think we saw two living spiders, a moth, a few mud dauber nests, and some ghastly slime, but that’s about it.
It is impressive how extensive the tunnels are…and we never really notice them. Apparently we can get to every building on campus without stepping outside, except that most of the access doors are locked for safety reasons: there are asbestos covered pipes everywhere, cables snaking around the ceiling, and hot metal supports that it would be unwise to touch.
But now I know how to get into them whenever I want!