You're in a large room carved out of sedimentary rock. The floor and walls are littered with bits of shells imbedded in the stone. A shallow passage proceeds downward, and a somewhat steeper one leads up. A low hands and knees passage enters from the south.
[UPWARD] [UP] [U] [ABOVE] [ASCEND] [HALL] [D] [DOWNWARD] [DOWN] [DESCEND] [SOUTH] [S]