The closeby area to where you spawn consists of a high amount of extreme hills and mountains. If you look up in the sky you will see a couple of large floating chunks of dirt and stone. The biome as a whole is quite compact which makes the terrain more exciting and fun to explore.
This is the beginning of the biome close to where you spawn.
To get here you need to walk a little bit further. As you can see, it is a pretty cool extreme mountains biome.
If you find anything cool, make sure to let us know in the comments!