Dectus Medallion (Right) is a Key in Elden Ring.
Right half of a split medallion depicting the Erdtree.
Brandishing the medallion with both halves conjoined will activate the Grand Lift of Dectus, connecting the Altus Plateau to Liurnia.
The left half is said to reside in the coastal Fort Haight to the far west.
Elden Ring in-game description
Dectus Medallion (Right) Location

Additional Insights Into Dectus Medallion (Right)
- Effect: Join medallions to operate Grand Lift of Dectus
- Rarity: Rare
- Sell Value: 0 Runes
- Dectus Medallion (Right) can be traded.
- On-Hand Capacity: 1
- Storage Capacity: 1