Bowl caves like this are fairly common after you explore the world for a while, but when liked this spot a lot. There are some shallow tunnels beneath the place where I built the house, and I used this as a base to explore the larger cave system inside the bowl cave. It didn't go very deep (no diamonds). I did find a nice shaft where I eventually built some stairs up to a small summit where I spied a village in the distance.

That would be my next destination, and was the first village that I found in this world. Eventually I built some rails.