I added  bonus chest to my survival game with the cliffs and caves beta and couldn't find chest but some miracle I found it way below like around -44 around diamonds I'm not a noob to minecraft but to get the starter chest was pretty hard for a new player really chest was deep I literally dug down  didn't know World limit was changed in the cliffs and caves beta holy cow that's a new cave system to explore great job so my first time using the beta