Dragonspine is full of many quests in Genshin Impact, including some that won't be given by NPCs. These quests often help to unlock secrets in the mountain. One of these unnamed quests requires the player to find three treasure boxes hidden around the region in order to unlock a sealed door. These boxes are called the Princess's box, the Priest's Box, and the Scribe's Box.
Like the crystals in the Sky Frost Nail quest, these boxes are hidden in several different spots around the mountain, and one of them will even require the player to solve a simple but hidden puzzle. This guide below along with these wonderful pictures from @Bansugar on Mihoyo Tavern, make the quest easy to conquer.
Princess's Box ( Anemo and Pyro Recommended)
The first box is located on the small island in the picture above. In the middle of the island will be a sword hilt that the player can interact with. Doing so will summon three abyss mages that need to be defeated in just a single minute's time. This is a bit difficult, as only two mages will spawn at first, with the third spawning after the first two are defeated.
The first two mages are also cryo and hydro, which will have a high chance of freezing the player. The strategy for beating this challenge is by using an anemo character to easily knock the mage into the water right as their shield breaks. A Pyro character such as Diluc is also highly recommended in order to quickly break down the mage's shields. After they are defeated, simply open the chest that appears.
Priest's Box
The Priest's Box is simple to get; go to the location shown on the map above, where you will find a small ruined tower. Climb the tower and open the chest at the tops to receive the Priest's Box.
Scribe's Box
The Scribe's box is a bit of a puzzle and, for many players, easy to pass by. Warp to the location seen above and then walk down the path. You will notice a grave on the right side of the road. The player will need to have three Cecilia to place on the grave. Cecilia can be bought from Flora's flower shop in Mondstadt or found around Starsnatch Cliff.
Unlocking The Gate
The final part of the puzzle is simple, teleport to Dragonspine's statue of the seven and follow the path above. If you have already broken the crystal in Starglow Cavern, then you can teleport to the waypoint shown instead. Go to the giant stone door and hand over the boxes to open a treasure room. Inside the treasure room will be a luxurious chest, a precious chest, and a tablet that is needed to access another secret room in Dragonspine.
