Weirdness on the Isle of Nod


So I was searching around the Isle of Nod and I noticed a blood trail behind one of the houses.
It sort of led to this weird spot that was unclaimed by the town. It had no authority over it and I was able to chop down the tree on it.
I then wrecked the stump and dug it out thinking, meh, let's see what's down there.
Then this happened.
I ended up in this weird tunnel system in a sort of maze. I started to drain really, really fast. I didn't have a torch. It said "Entering The Labyrinth" like if you were entering Providence.
There were random doors or spots to click on, I hit one and entered into this room.
I was really low on biles. I only had a 20 stat alt, so instead of going back out I dumped my inventory and ported out. The hole is still there but I can't get back into it. WTF is going on out there? Has anybody else done anything like this?