So, serendipity strikes. I'll reformat it for here and remove some of the chatty verbiage.

There's a metro stop here called 舵落口, loosely translated as "rudder fall harbour". I asked someone who I was with what that meant since I knew all the characters (well, guessed at the first) and couldn't fathom what they meant together. He looked it up on his phone and the story that came out was this:

Hundreds of years ago, there was a lake here, and there was an immortal by the lake. One day, he stood on the bow of his boat and released a stream of black gas from a gourd. Suddenly there was loud thunder and his boat sank to the bottom of the lake, the immortal flying away into the sky. Local fishermen pulled up the sunken ship, but its rudder was missing.

Years later, there was a severe drought and the lake dried up. Fishermen found the fallen rudder under the sand near the sunken ship's wreck. The rudder suddenly turned into a red dragon and flew into the sky to bring rain.

People were grateful for the great kindness of the immortal's rudder that fell off the boat in the lake and turned into a dragon bringing rain down upon them, so they called this area the rudder drop harbour.

It had never dawned on me that subway stops could be such a treasure trove of local folklore. Guess who's going to investigate every stop now…