There's a lot to do in Genshin Impact, more than is readily apparent. It's often compared to Breath of the Wild, though this isn't entirely accurate. While both games hide a lot of content around the world, they do it in different ways.
There are a few different kinds of quests in Genshin Impact. The most obvious are the mainline quests that further the game's story. Then there are the world quests, which can be found by exploring the world. However, some quests are not immediately obvious, and don't become so even as they're being done – one of these is the quest for the Nameless Treasures.
Step 1: The Treasures
The first thing to note is the nature of the Nameless Treasures themselves. Each one is acquired in a different place as part of a different quest or puzzle, and their use is not readily apparent. Doing multiple quests is a good way to increase adventure rank, so there's a good chance players have come across these quests already. There is no detail tying the Nameless Treasures to the quests, so a little detail for each quest is needed.
Step 2: Dunyu Ruins
The first of the Nameless Treasures can be found at Dunyu Ruins. These ruins are in a landmass at the center of a lake, similar to the area with Vermeer's Paintbrushes. There's a geo switch at the ruins, but it's blocked off. To get to it, players must light four torches. Afterwards, players will encounter a barrier around some treasure. Three blue spirits must be found around the area and guided to the barrier to open it. The Nameless Treasure is part of the uncovered hoard.
Step 3: And This Treasure Goes To
The above is the name of the next quest. Players must go to Lingju Pass, where there is a woman locked in a cage. Make sure to have Genshin Impact's elemental counters memorized, then clear out a monster camp to get the key and set her free. She mentions a buried treasure nearby, which is buried under a tree in the ruins at Lingju Pass. The Nameless Treasure is in it.
Step 4: Qingxu Pool
The last puzzle is at Qingxu Pool. By now, Genshin Impact's fast travel system has no doubt proven useful, and it will be useful one more time. There are five towers at the ruins of Qingxu Pool, and atop one is a stone telling you to hit five Geo switches. The first is right there, with another at the top of each tower. A chest will spawn from this with the Nameless Treasure in it.
Step 5: Selling
The last part is cashing in the Treasures. Head to Liyue Harbor, wait until 9:00 PM in-game time, then find the Antique shop. Players can sell all three Treasures here, and it's best to sell them all at once for more reward.
Genshin Impact is available for PC, PS4, and mobile.
Source: Gamers Heroes