Royal Waterways

A massive cavern filled with Geo chests, paintings, a statue identical to the one where the Monarch Wings are acquired, and assorted piles of other trash washed up by the currents. This pile of rubbish is said to be Flukemarm's treasure by Fluke Hermit who is also found within this area. Though among all the worthless junk lies a golden sarcophagus which, when opened by a Simple Key, reveals The Godseeker where she has been hibernating. Accessible by breaking a roof on the northwest corner of the square-like area next to Flukemarm's boss room. A wall at the top of the Junk Pit can be broken to reveal access to the City of Tears, below the Nailsmith's forge. If the Nailsmith is killed, his corpse appears afloat the Junkpit waters, near the shore.

Trivia
 * There is an unused key in the game's files labelled "Waterways_Key" which was presumably used to open Royal Waterways instead of the currently used Simple Key.

References

Voies d’Eau Royales Королевские стоки Canales_Reales Królewskie Arterie Idrovie Reali