Through Goblin's Gate
Kobolds of the Urlbluk tribe haunt a region known as the Wormwrithings, a place full of tunnels that purple worms bored in the stone and earth. The kobold presence in the city means that some previously unknown passage has opened to link the city to the Wormwrithings. This prospect promises far greater dangers than kobolds.
Before the fall, the dwarves gathered precious metals and gemstones from fresh worm tunnels bored through the rock. Gurmadden Stonesinger hopes the adventurers can do the same and bring back five Singing Stones that dwarven bards sing with. He hopes to use the stones to help him rebuild the the Singing Stones.
To aid the group in accomplishing the goals, the dwarves give a mining pick to anyone who wants one.
Past the barricades, the southern tunnels of the ruined city are eerily quiet, except for the constant muttering of your guide and the sound of your footsteps. The caverns are lined with shallow caves and through narrow tunnels with low ceilings.
The passage to the Wormwrithings is a fissure that opened up a century or so ago in the southeastern corner of the Foaming Mug caven. Where it begins, the fissure is twenty feet wide and almost as tall. It then goes south before narrowing a few hundred feet past the entrance. After narrowing, it continues south and gradually winds southwest to the Wormwrithings.
At last, the passage opens into the side of an enormous circular tunnel, winding off into the darkness in both directions. Jutting from the rock just across the tunnel, you spot a gleaming crystal like the ones Gurmadden showed you.
Passages here are twenty feet in diameter, with smaller natural passages breaking through the smooth walls at various points. The worm paths often cross each other from unusual directions, including vertically. Passages extend for anywhere between forty and several hundred feet before changing direction. Creatures can walk normally across the center ten feet of a worm tunnel, but the sloping five-foot edges to either side are difficult terrain.
Each hour the characters stay in the area, roll 1d10 and consult the table: