here’s a guide I wanted to post here
the guide is how how to make an underground base, hidden from everyone on the server.
as you can see, here I’m underground in a singleplayer world for demonstration purposes
I dug to the side as far as I could, and made it so the corridor needs to be lit up for you to see.
Try and guess what item I have placed there before you keep scrolling, you won’t be able to.
here’s the area lit up
I did not move the camera at all, i simply placed a torch. if you use this concept with trapdoors, I have no doubt your base would be safe from nearly everyone. It would even be safe from admins provided you weren’t inside the base or it was lit up