(Very strange...)

This map is recent and I discovered a lot of strange things on it when exploring. I started a world with a random seed and then the game started loading the world. As soon as I entered, I spawned inside a cave like WTF and then I went out to get some wood. I found a lot of it. I started getting it then I noticed when I broke a cross right on the side of the rim that I broke I was very scared but I continued and found other things out there so you can discover this world is not normal I was taken a lot of resources to make my house then I I closed the game and didn't go back in and all of this was found in the most recent version of the game, the most current