Hollow Knight, a Metroidvania action-adventure game developed by Team Cherry, follows the exploits of a nameless warrior known as the Knight as they travel over Hallownest, which has been devastated by a terrible infection. As the Knight goes around Hallownest, the Knight can obtain new items, abilities, spells, and charms, allowing him to explore new areas and battle enemies.

Mask Shards are an example of these in-game objects. These Mask Shards are required to enhance the health Masks of the Knight.

To complete one Ancient Mask, the Knight must collect four Mask Shards. Completing one Ancient Mask will add one to the Knight’s health.

Because there are a total of 16 Mask Shards in the game, the Knight can have four more Masks of health for a total of nine Masks (excluding Charm effects and Lifeblood Masks).

There is actually only one Mask Shard that can be found in the Royal Waterways, and in this guide, we will learn how to obtain the Mask Shard in the Royal Waterways area!

Royal Waterways Mask Shard

The Mask Shard in the Royal Waterways can be found inside a hidden part of the bottom left corner of a room near the northwesternmost part of the map of the Royal Waterways area

In Royal Waterways, the Knight will encounter a variety of opponents, but on the way to the Mask Shard, the Knight will specifically encounter Pilflips, a Belfly, Hwurmps, and Flukemons.

Before the Knight can find the Mask Shard in the area, the Knight must have the Desolate Dive spell or the Descending Dark spell (which is the upgrade to the Desolate Dive spell), which allows the Knight to strike the ground with concentrated Soul, the Mantis Claw ability, which allows the Knight to cling to walls and jump off of them, and the Monarch Wings ability, which allows the Knight to perform a double jump in mid-air, or the Mothwing Cloak ability, which allows the Knight to perform a horizontal dash forward.

To light up really dark rooms, the Knight must also purchase the Lumafly Lantern from Sly in Dirtmouth. Finding the Mask Shard in Royal Waterways will be a breeze with this item, spell, and these abilities.

To find the Mask Shard in the Royal Waterways, this is what the Knight must do (this is assuming that it is the Knight’s first time in the area):

1. From the Memorial to the Hollow Knight in the southern part of the City of Tears, head to the left, take the exit, continue heading to the left, then take the exit that leads downwards.
2. The Knight has now arrived in the Royal Waterways. Upon dropping, head to the left, where the Knight will find two Pilflips; at the end of the path, head down the shaft, where the Knight will run into another Pilflip and take the exit on the left.
3. Then, head to the left, drop down the gap, drop down the next gap on the right, then, at the bottom, you will see that the ground will rumble, which means it is breakable. Cast the Desolate Dive or Descending Dark spell on the ground to break it, head to the bottom of the shaft, and exit below. 
4. Next, the Knight will land next to a crooked Bench. Sit down on the Bench to save your progress. Afterward, head up the shaft above using the Mantis Claw ability and return to the previous room.
5. Then, head up the shaft with the help of the Mantis Claw ability, take the next path on the left, head to the left where the Knight will find a Belfly, and jump across the gap towards the platform above on the left where the Knight will find a Hwurmp, jump across the gap on the left towards the platform below on the left where the Knight will run into two more Hwurmps, jump across another gap on the left towards the platform above on the left with the help of the Mothwing Cloak ability or the Monarch Wings ability where the Knight will encounter two more Hwurmps, then jump up towards the platform above on the left with the help of the Monarch Wings ability or the Mantis Claw ability where the Knight will find another Hwurmp.
6. After that, head to the left, drop down the gap where the Knight will find a Flukemon, continue to the left, jump up the platform, drop down the shaft on the left where the Knight will run into another Flukemon, head to the left, head up the shaft using the Mantis Claw ability, and take the exit at the top on the left.
7. Next, head to the left, drop down on the gap, swim to the left towards the next platform, drop down the gap on the left, continue to the left where the Knight will run into another Hwurmp, jump across the gap where the Knight will find another Hwurmp, head to the left, jump across another gap towards the small platform on the left where the Knight will find two more Hwurmps, and jump across another gap towards another small platform on the left (it is worth mentioning that there is a Geo Chest above next to a Hwurmp).
8. Then, drop down the gap on the left, land on the water, swim to the left, pass through a narrow opening, then jump up the next platform on the left.
9. Finally, head to the left, and there the Knight will find a Mask Shard. The Knight can now jump toward the Mask Shard to acquire it!

Now that the Knight has obtained the Mask Shard in the Royal Waterways, the Knight now only needs three more Mask Shards to add one more Mask of health!