Indoor Survival Mod?

Hi,its my first topic on the forum,i just wanted to know if there’s any mod that add’s an underground/Indoor big area to explore and survive on,kinda like the lab start,i got this idea after seeing the backroom’s mod for Project Zomboid and it seens really cool to be limited to an closed area,so i was wondering if something similar to that already exists.
Thanks in advance and sorry for any misspelling.

Well, there is a mall start. It is indoors and can be generated quite big.

That is to change the scope of shopping malls in defense mode and add some more things