I am making/placing portals in the nether every 125 blocks so I have a checkpoint of portals every 1000 blocks in the overworld.
The Y axis of my portal are is at 120, like in the screenshot below.
Now, when I entered that portal, it spawned me inside of the cave.
(the screenshot shows no portal on it since I removed it, but the obsidian is the original location of the spawned portal)
I decided to dig straight up and try to look for a reason why I spawned in the cave and I'm just seeing an area that is perfectly fine for a portal to spawn in.
My question is why did the game decided to spawn a portal in a cave? Are there some checks that the game does? All I know is if it has a space for it, it goes there.
If it matters, the game version I'm running on is 1.14.4.
Best Answer
Nether portals prefer generating on the same height as in the other dimension. So if you create your portal below y=64 in the Nether, it is likely to be generated in a cave in the Overworld.