If you explore east of Genshin Impact's Port Ormos and south of Devantaka Mountain, you'll find a Dendroculus trapped inside a Dendro Barrier. To unlock it, you must solve a quick puzzle using one of the Aranara songs from the Aranyaka questline.
How to get the Dendroculus inside the Barrier in Port Ormos in Genshin Impact
Before starting this puzzle, make sure that you have the Vintage Lyre and have unlocked the Rhythm of the Beastly Trail. To get them, you must complete The Rhythm that Reveals the Beastly Trail World Quest:
While you will learn the song after part 1, you need to complete all three parts to fully unlock the Rhythm of the Beastly Trail.
Once you've done the prerequisites, head to the puzzle location east of Port Ormos, circled in the image above. Equip the Vintage Lyre and approach the Claustroflora, the blue flower in front of the Barrier. Activate the Vintage Lyre and follow the in-game prompts to play the Rhythm of the Beastly Trail (do > so > la > mi > do on the third line. Doing so will disperse the Dendro Barrier, allowing you to get the Dendroculus inside.
Check out our guide on How to solve the hidden Dendro Barrier Luxurious Chest puzzle in Mawtiyima Forest in Genshin Impact to complete another Barrier puzzle in Sumeru.