The Tavern

From docs/develop/levels/introduction.txt: "If you do not want a vault to be randomly generated, do not assign it a DEPTH. If the vault is in a des file with a default-depth set, you can force it to have no DEPTH setting with an empty DEPTH: line."

So you'd give the parent vault a valid DEPTH: so it can be randomly placed, but set an empty depth on the accessory vaults so they won't be placed until you explicitly request them by tag.