Oozes are one possibility.
You are in the center of a huge area. The closest wall is 40-50ft away.
Only, and
only, because you rolled a 20. (Once again, background plot falling into the hands of the dice. Not that any of this matters.)
Back during the great war, when Gahst and Frais were the same country, Frakas was nothing but a military shipyard. Its dry-docks were able to lift whole ships up to be built, repaired, or just loaded. Instead of just being single-ship dry-docks, they would have the ships for a whole fleet come in one at a time, lifting each one up, with the flag-ship last. When the docks were no longer needed at the end of the war, they were preserved (in case they were needed again), but built over (mostly to not waste space).
That was, literally, DC 30 Scholarship.
Well-maintained, but old.
Basically, the area works like the panama canal, but the roofing would get in the way of a bunch of the 'plates' from raising too far. First one to ask whether the roofing is actually stronger than the plates lift mechanism gets a cookie. First one to try to find out
without asking, earns the title 'Ultimate Enforcer of PC Logic'.