World boundaries
Note: This article is accurate for Minetest version 5.0.0. Other versions may differ.
Minetest's world is not infinitely large. Therefore, you can theoretically reach the world boundaries if you just travel far enough. But you would need a fairly large amount of time and a lot of determination to actually reach a world boundary just by walking, building or digging. A world boundary is an invisible barrier which cannot be passed by normal means. This can be made possible by using no-clip mode and fly mode.
Minetest's world is a huge cube with a side length of ca. 60000 blocks. Each dimension (X, Y and Z) ranges from −30912 to 30927.
Beyond the world boundaries, no block can be placed and there is just an endless void.
You can view your current position by pressing F5 (Debug) on your keyboard.
Edges of the world
The 4 edges of the world are the 4 sides on the horizontal plane. They are located at X=30927, X=−30912, Z=30927 and Z=−30912. If you try to walk further away, you simply collide with an invisible barrier and cannot walk any further.
Bottom of the world
The bottom of the world is located at Y=-30927 and behaves a bit weird. If you actually reach it, it looks like you are facing an endless gray or black abyss. Players can actually walk on it safely and won't drop any further. But dropped items, falling blocks (like Sand) and other objects falling through will disappear.
Top of the world
The top of the world is located at Y=30927. But you can't actually get higher than Y=30926, this is because the player has a size of roughly 1×2×1 cubes and thus the head is colliding with the top of the world.
