Bedrock (idk if it’ll work in Java) 1106523946111373332

I found this in survival mode with mods and got so confused when I found this
I went into creative mode without mods to see if it’ll still be there and it was
I found different colors of terracotta, mud bricks (and other mud items), bricks, cauldrons, furnace, blast furnace, a single brown stained glass, a ladder, smooth stone slabs, and more things
I’m still not done exploring everything this thing has but some parts looks like it’s suppose to be rooms but idk
What in the world is this suppose to be?