Unity3D tutorial: How to make and import a terrain using L3DT
Website: http://www.czorio.com/
This video shows you how you can make a goodlooking terrain for use in Unity3D.
L3DT : http://www.bundysoft.com/L3DT/
Unity: http://unity3d.com/
Any external music comes from either Incompetech.com or Machinimasound.com