Horizontal Pole Shot

Normally you mount your camera on top of your pole to reach a more elevated viewpoint above the ground. But if you tilt your pole ~90° and point it over a railing or a cliff then you are doing a horizontal pole shot.

You can also use this technique whenever you want the nadir over an area where you can’t stand. For example like in this panorama where I used this technique to place the fumarole in the nadir.

Also see a detailed description on horizontal pole shooting at 360texas.com.