Are you using perlin noise?
Viewing post in Minecraft [UNITY RECREATION] + Unity Project comments
In a way, yes. Except not Unity's built in Mathf.PerlinNoise. As that method generates 2D noise. What i did was i used a 3D perlin noise script (that was not made by me) and modified it to be more concentrated the lower the y axis is, thus making a hilly terrain. I used the same algorithm but without the y axis modification to generate the caves, as well.