Alt Harbor is the island in Spiritfarer where Stella first appears after talking to Charon at the Everdoor. This is where Stella encounters Gwen and acquires her boat.
The remains of an old Shipyard.
An old Harbor that's been cleaned up.
Hummingberg Preservation Society
This shenanigan is given here sometime after Stella unlocks the blueprint for the Windmill. The quest reward is the blueprint upgrade for the Windmill.