SC3K Map Editor 1.2Free
SC3K Map Editor is the fastest and most accurate terrain editor currently available for SimCity 3000. It gives you the finest possible control over modifications to your terrain.
With SC3K Map Editor you can use an interface very similar to that given by SimCity 3000 so that you can see exactly what your terrain will look like as you create it.
Also you can make your layout suit your purposes and techniques.