Head to the eastern Davon’s Watch. Just south from the nearby dock, you will find a hidden cave entrance. Inside the cave find and use Strange Chest. Upon using it, a portal to Crow’s Wood appears. If for any reason you don’t see the strange chest surrounded with red light on the ground, or the portal itself, try logging off and on. once inside, jump into water on your left. Keep walking West. Collectible is almost on the edge of the map, behind a rock formation, in water.
Hidden cave entrance can be approached from the ground level, near water.
Hidden cave Map Location
Head toward this Strange Chest and use it.
It reveals Crow’s Wood Portal. Use it to enter a public dungeon.
Jump into water and head southwest.
Something is well tucked behind a rock structure in water.
Sand Kingdom Moons - Super Mario Odyssey Power Moons