Change lighting in one section manually?

So I have a scene where there’s an underground “crypt” that I wish to have lit with torches. Right now, it’s very bright in there, despite all sunlight being blocked off. Is there a way I can create some sort of lightmass volume that changes it to be much darker ambiently once inside, with most light coming from the torches? I tried the lightmass importance volume, but it still left that section quite bright. Thanks in advance!

Hard to see whats going on without a picture but do you have a skylight in the map? If so reduce intensity. If the brightness is coming from baked light maps, you can remove what you did and start over. Make sure to put a solid mesh all around your cave where directional light will not be entering.

To remove lightmaps go to world settings/Lightmass and click Force No Precomputed Lighting and bake lights twice. Should instantly remove your lightmaps. Adjust lightmass values in world settings also to get darker results.after you try baking again.