Just below my base I found something awesome.
It was a dungeon with a zombie spawner in it
I can make a great XP farm out of it, and get a lot of cool stuff from the chests hiding inside. The best part of finding this dungeon is that I can also get villagers out of it. Some of the zombies are zombie villagers and with the right potion and a golden apple, you can convert these bad guys to good guys that can be helpful in trading and eventually, you can make an Iron Golem farm with them.