Time for the fifth instalment of Inkwell Ideas Geomorph Contest. This entry's secret ingredient is "water," which is one of my favourite dungeon features.
At minimum, water is a physical obstacle--it has to be crossed, entered, slogged through--and PCs hate to get wet. Armoured characters can sink to the bottom, those unarmoured may get swept away in a current. Depth is never known until tested (dwarves and halflings beware). Water ruins equipment, dissolves potions, and spoils food.
As if all that weren't enough, water in the dungeon always hides something within its invariably murky depths. Submerged pit traps, fish with sharp teeth and ravenous appetites, tentacled gill-beasts, even giant clams that clamp shut on too-slow thieves grasping at their fist-sized black pearls. My college campaign contained a tomb with a horde of submerged skeletons that rose up from both sides of a dry passage to attack PCs as they crossed. It seems like such an obvious trap--I mean, you're in a tomb, you know there are undead, and you're about to cross a 60' passage lined on either side by deep pools of murky water--yet even when I run this dungeon today, the PCs are caught unawares every time.
A trickle from the north fountain has flooded the lower halls, and the light blue squares are submerged to a depth of 4' (movement slowed to 1/2). There is a 4/6 chance that the lead character loses his footing on the submerged stair leading to the dark blue area, which is flooded floor to ceiling (if armoured, he risks drowning). The glyph in the central chamber cannot be read while submerged, but the crank behind the portcullis in the west opens the floor grate, draining the water in 7-12 turns. The sigil provides a beneficial magical effect (GMs should roll a random potion and apply the effects to each PC for 5-8 turns).
Design-wise, I feel good about the lack of symmetry, and I think the colours work. But while this was the fastest entry (two hours from concept to rendering to write-up), I don't think it's my best effort--somehow, it seems more straight-forward (thus boring) than previous entries. Maybe it's the long passages. Maybe it's the lack of animal pens. Maybe it's just me. Anyway, thoughts welcome.