The royal palace of Ryugu Kingdom on Fishman Island. King Neptune, princes Fukaboshi, Ryuboshi, and Manboshi, and princess Shirahoshi used to live here. It is apparently located in the smaller bubble that sits on top of the main bubble surrounding the island.
The place where the mermaids gather and socialize. They live in a coral mansion on the sea floor of Fishman Island, and the employees of Mermaid Cafe live in a same dorm in the cove.
The Sea Forest is a place northeast of Fishman Island known as the Ship Graveyard. It has a lot coral growing around it, more so than normal due to the light emitted by the Sunlight Tree Eve. It is populated by all kinds of sea fauna, including schools of fish and pods of whales. There are also several shipwrecks there because sunken ships are dragged there by the ocean currents, thus the epithet "Ship Graveyard".