Collectible is inside Bruma area. This is a rather large keep, almost matching in size some fortresses. You can spot it from the distance by its large stone walls and towers. Stone houses inside Bruma are even taller than the nearby walls. Collectible is in western Bruma, behind the largest house in Bruma, inside a fountain like stone structure. Be aware of hostile elements of Bruma. Enemies inside the keep do not like unannounced visitors.
Inside Bruma area.
Behind the largest house in Bruma.
The collectible map location.
Zoomed out map view.
Sand Kingdom Moons - Super Mario Odyssey Power Moons