What's up next? You know how to place vegetation to create a forest, you know how to place objects and prefabs, you know how to texture terrain, and modify it. How about making use of CryEngine2's voxel ability to make cliffs and caves in your terrain? It would certainly liven it up. OK, first of all run this console command -
The console is below the perspective view. You should now see a bunch of coloured boxes in your view. These are called terrain sectors. But now we want to make cliffs and caves. So in the objects view, click on Misc and create a VoxelObject. Place it near those mountains you created, use the red box that appears as a guide. If you can't see a red box, press Shift+Space to show it.
Now we can actually paint voxels inside the red box. So click on the terrain tab on the RollupBar and click on 'Voxel Painter'. Make sure type is set to create, and start painting some voxels. See if you can create a cliff. If your voxels turn out black, make sure that 'ground' is slected as the surface type you want to use.
As you can see if you experiment enough with voxels, you could create a whole variety of new shapes, not just cliffs. Let's create some caves now. First we need to create some holes where our cave will open. So go into the terrain tab and click on 'holes'. Set it to 'make hole' and then 'paint' one some holes where your cave opening will be.
Now create another VoxelObject and place it in the same way you did with the first. You might want to rotate it so that the box encompasses more of the mountain. Once you've got it where you want it, click 'Copy Terrain into Voxel' to copy the heightmap data into the voxel object. As you can see, the hole you made disappeared. This is because the voxels are covering it.
As you can see, the voxels are flashing. Don't worry; this is just because it is selected. Now go back to the voxel painter tool, and change the type from create to subtract. Now you can carve out your cave. Here are my results:
Now, move your camera low over some terrain and go ingame (CTRL+G). Explore the inside of your caves and even to tops of your cliffs.