How to desactivate Sky atmosfere when inside building?

Hi, im creating an openworld game where you can go inside dungeons, and i wanted to be pitch black when inside, but the sky atmosphere makes this wierd fog when im inside dungeons:

When I desactivate the sky atmosphere I get the result im looking for, but then i lose the atmosphere outside:

How can i have this effect without losing the outside atmosphere?

Ps: its going to be a multiplayer game, so im looking for a solution that doesnt affect the players that are outside

Thank you in advance.