I was planning to do three geomorphs on one concept on Map Monday, to finish out the F Series; but then I realized I had missed a theme. Rather than post all three geomorphs on Monday, I'll post two today, then post the final one on Monday.
These two geomorphs are built around a theme similar to the pools of water or liquid I did last Monday, but with a thicker, bubbling liquid. I'm calling it "tar", but originally I was thinking of it as lava; it could also be hot mud or effervescent slime or anything else. F16 is a pair of rectangular pools of tar blocking two different passageways; under the larger tar pool is another corridor, which leaves open the possibility of a mild, slow drip from the pool into the corridor below. There's also a side passage to the lower corridor with a couple small chambers; and because I hardly ever put rooms in the corners of the geomorphs, I've added a secret room this time.
Geomorph F17 is a cavern version of the viscous liquid pool theme, which might be more reasonable to use for lava pools than the rectangular one. One large cave with one large pool; one corner of the cave has a ledge that overlooks the pool; ledge access is via two different tunnels, neither of which connect directly to other tunnels on the geomorph. Explorers could risk diving into the pool to reach the lower level. There's also another tunnel that passes under the cave, but not directly under the pool.
As I already mentioned, there's one more 10x10 geomorph Monday, but I'm also considering doing some borders and corners in the F series, which I'll either post with F18 or include them in the F-Series PDF without comment, since they'd all be very simple pits, pools, and grates that wouldn't need much description. The PDF should be available Monday or Tuesday.