A twisty little cave network with a pretty nasty trap for the big-folk what come meddling...
This map has a few features I feel like pointing out for all you vicious DMs out there. First and foremost, only the tunnels leading to the trap chamber are large enough to fit a human-sized creature - all the other tunnels are only large enough for a kobold or goblin to fit comfortably. Anyone larger will be squeezing quite uncomfortably, and unable to swing a weapon or defend themselves properly.
The small tunnels overlooking the main trap area provide three-quarters cover to creatures inside them, making them perfect ambush points for big-folk that get stuck in the trap chamber.
The central chamber is a mixing pot of trouble for interlopers. A sudden cliff drops unwary intruders onto a pile of scavenged shields, causing a tremendous clatter and alerting the warren. Other tunnels splitting off the central area give interlopers something to explore while the clan gets into position. Two of those tunnels end in steep cliffs (again), and one ends in a deep pit the kobolds use for garbage and refuse.
If all goes according to plan, the intruders will return to the central chamber just in time to receive a withering enfilade of crossbow fire. If that doesn't work, the clan shaman summons something foul from the Big Pit...
I'm busy working on my blog posts. Watch this space!