This is one of those shards that you can’t miss. That is, if you are following the main road. The name heavily hints towards the location. One may wonder if the name came before the location was even set, or was it the other way around.
Just head north from the Molar Mag Wayshrine. There is a small ascending part, that takes you to the top of the hill. As you pass by the short blue fire brazier, the path will go downhill, right toward the shard. Its glow is a bit hidden by the large rocks next to it, so spotting it might be a problem if you come from the other direction.
Sand Kingdom Moons - Super Mario Odyssey Power Moons