MCSS

The MCSS! Has several rooms, like:
Power Generation
A WORKING elevator
A laboratory
And more!
It has sabotages, redstone, lights, and closeable doors!
This is not 100% complete, so it may have an underwhelming amount of rooms. It is still being worked on though!
Only available for 1.16.x due to its heavy use of the netherite block.
It says it's 15% done because I really don't know how finished it is. I just keep working on it.
You can't use this as a .zip file, you need to open it, go into the MCSS Versions file, then copy/paste the version you want.
There will be two .txt files there, too.
One of them tells you which mods you will need, and the other one is a change log.