So I'm trying to make a simplified Terraria style world using Perlin noise. I got that working and the terrain is randomized. However the terrain always looks like like a weird cosines curve. Hills and bottoms with different heights repeating. The effect I want to achieve is something similar to this:
Where the terrain is mostly flat looking and sometimes a large mountain will appear.
Is there an algorithm or "noise" that could achieve this effect or what other things do I need to do?