While exploring the area of Act I in Baldur’s Gate III, you’ll eventually come to The Risen Road which is northwest of the Druids’ Grove. If you enter the building across from the Ancient Sigil Circle, you’ll find an Ornate Wooden Hatch on the floor immediately to the right. Interacting with the hatch will take you down to the cellar where you’ll spot a giant Vault Door. Unfortunately, that bad boy is locked up tight. Luckily for you, that’s where our handy How to Open the Vault Door in the Budiling on the Risen Road guide that you are reading now comes in handy 🙂
Outside when facing the building, follow the walkway around to the right. You should spot a ladder there leading down the side path off the mountain. Climb down and locate the body of the Dead Toll Collector. Next, you want to cast Speak with Dead on it and exhaust all of the dialog options. The guy will tell you that he dropped a key to the vault down the mountain. You can get the Speak with Dead skill by wearing The Amulet of Lost Voices found in the Dank Crypt. A guide on that can be found here if you need it.
Otherwise, you can just head down the slope swinging a right to reach the location in the image below.
You can find the key on the ground there. Pick it up and return to the Vault Door then stick it in the keyhole!
