The Dancing Bridge

From Introduction:

The land here has been split by a deep ravine, extending in both directions as far as you can see. A bridge, consisting of floating platforms, spans the ravine. On the far side stands the fragmentary ruin of an amphitheatre.

You can clearly hear the resonant voice of the malformed humanoid who stands within as a challenge is issued: "Halt, mortals! Come no further! You stand upon the very brink of the sovereign fey lands of Owella, the Deathsinger! Turn back and never return, or be slain."