Collision with the Terrain

Hello,
I set the physics to some objects, and the collision between them is ok. But I made them all floating, without any gravity.
Now I want to add a terrain (a simple one, nothing sooo big) to the scene, but I don´t know how to create the physic object for it.

I found in the tutorials the example of the collision with terrain using Ray:
http://www.ogre3d.org/wiki/index.php/In ... _Detection

Is this the best way to do that?
Because in Irrlicht+Newton I used to map the terrain to a physic object, but I didn´t find it out on ogre.

I´m using ST_EXTERIOR_CLOSE for the scenemanager. Is this one correct?

Thanks!