human
Generate a description of a chilling wilderness scene with a stone dam and a gap in the top.
assistant
A stone dam blocks the north part of the tunnel, keeping the bogwater collected on the muddy floor from seeping any farther. At one time the dam might have covered the entire opening, but stones have fallen inward so that although the lower section is blocked, a hefty gap has opened at the top. Chill air wafts over the stones, a bit more fresh than what the rest of the tunnels offer.