Cursed Tomb Treasure
This one is in the huge Manor located in the Manor Cape region.
Go to the main entrance where the Ancient Magic Hotspot is.
Enter through the main doorway and go left.
You will come across some stairs. Go down until you find a level 3 lock.
Unlock the door and keep going forward. You will encounter many Inferi and an infamous Ashwinder foe called Ailsa Travers. So be careful when down there and prepare for a duel.
After defeating the enemies, look to your right, where Ailsa Travers spawns. You will find a chest with a treasure map.
Next, fast travel to the Tomb of Treachery floo flame on Poidsear Coast.
Enter the Tomb of Treachery and keep going forward until you come across an open room with a tomb in the middle and Photine's Second Note.
From here, look to your left and clear the spider web using Confringo or Incendio.
Once through, you will find another locked door and a bunch of spiders.
Now, go to the room to your right, and you will find a mechanical fly.
Return the bug to the locked door and turn off the light on your wand.
Go back to the same room, and you will find another crane fly behind some spider web.
Now, go to the room to your left. But first, clear the web using Incendio or Confringo spell.
You will need to get up on an elevated surface. You will find a wooden box to your left which will also be resting behind some spider webs.
Use the Wingardium Leviosa spell (or cast and hold Acio on the box, which converts into Wingardium Leviosa) to bring the box near the elevated surface and place it there.
Bring the final bug back to the locked door, which will unlock it.
Once you're inside, you will be welcomed by a number of Inferi. Take them out before you proceed with the puzzle-solving.
Now, open the treasure map you got from the Manor's chest. You will notice that the pattern shown at the bottom left also has a Flipendo spell icon on the left side. You will find a similar pattern on the floor in this new room you just entered. You must match the floor pattern with the one on the treasure map.
If done correctly, a chest will emerge out of the ground that contains the Treasure-Seeker's Attire.
The Hippogriff Marks The Spot
Fast travel to the Poidear Castle floo flame in the Poidsear Coast region.
You will find plenty of poachers here. Defeat them and retrieve the rolled parchment from the table at their campsite.
Next, go to Henrietta's Hideaway, located in the southern section of the Manor Cape region.
From the main courtyard of the building, look to your right, and you will find a small pathway that leads to the side of the building.
Keep going, and you will come across a door that takes you inside Henrietta's Hideaway.
Go inside and keep progressing until you find an open room with two platforms and a cube on one of the platforms.
You will find a statue to your left with a brazier at the base. Use Incendio or Confringo to light it up.
Use Wingardium Leviosa to pick up the cube and bring it on top of the second matching platform in the middle of the room.
Now, use Incendio on the cube with the Incendio spell icon (left) and Glacius on the cube with the Glacius spell icon (right).
Go through the door and fight off the Ashwinders, including an executioner.
You need to light up the braziers around the statue to match the pattern on the treasure map to get your treasure.
You can use Glacius spell to extinguish all the lit braziers and use Confringo to light them up individually.
Once the braziers are lit as per the pattern shown in the treasure map, the wall behind the statue will disappear, revealing a chest.
Solved by the Bell
Now, the next treasure map is also inside Henrietta's Hideaway. Continue going deeper into the dungeon.
You can counter this path by applying the Arresto Momentum spell on the path ahead of you.
Continue going forward until you come across another open area with a number of Ashwinders. Defeat them all before proceeding.
In this open room, you can see the map marked as a side quest through the wall.
Walk up to the wall to your right, and it will open up.
As soon as you're in, you will find the Musical Map on the table to your left.
Next, go to the Clagmar Castle in the Clagmar Coast region.
You will find multiple strong enemies here, including an infamous foe named Silvanus Selwyn.
Once you've defeated Silvanus, you will find a set of bells on the wall nearby.
You need to hit these bells in a certain order for them to play the classic Harry Potter theme. Follow the following order to successfully complete this puzzle.
If done correctly, a chest containing Treasure-Seeker's Longcoat will drop to your left.
Rowland Oake’s Map
This one is not exactly a "treasure" map but more of a direction to reach Rowland Oakes as part of the side quest called The Tale of Rowland Oakes. To start the quest, head over to the Transfiguration Courtyard in the Astronomy Wing.
You will find Adelaide Oakes in the courtyard.
You will be tasked to go look for the clues at a campsite to find the clues about Rowland Oake's whereabouts.
All you need to do is go further south to Korrow Ruins. There is a Korrow Ruins floo flame and a bandit camp castle.
Fly on your broom to reach the top of the goblin outpost, and you will find an entrance to enter the castle and continue your quest.