Kaniwa is the capital city of Bubalook Island. It is known for its large population, its great economy and its number of performers and merchants, and is mentioned in the description for Clown Lessie.
This may be the port city where the Searchers reunite with Captain Horn outside of a saloon in Episode 62. From there they find his pirate ship and sail to Kawrea. This may also have been the same city where Pink Jam and the Jells worked at a small restaurant.