Can I rotate a Terrain object in 2D project?

My project is 2D. So the camera is orthographic, I want to use a 3D terrain in my scene. So I add a terrain. But if I want to show the terrain correctly by orthograhic camera, I need to rotate it around the X axis. So I set the Transform Rotation, but nothing happens, it does’t work! Is there any way to do this?

You should be able to rotate it. In editor, I mean.