human
Write a detailed description of a mysterious tunnel passage with lichen and large gates.
assistant
Lanterns hung from closely-spaced wooden beams supporting the dark sandstone walls and ceiling illuminate the wide tunnel. Broad enough to permit the passage of three or four horses walking in tandem, the tunnel ends in a pair of large gates. A few tufts of lichen adorn the beams, scratch-marks on the wood revealing that the lichen is regularly removed.