How to transform Landscape?


I’m having trouble moving my landscape along the Z axis. I’ve tried using the transform tool in the editor, but every time I hover over it, the cursor turns into a red circle with a cross through it, symbolizing I cannot move the terrain. The transform section in the details are grayed out as well, not allowing me to change the values through the details panel. I’ve been looking around for a couple days, but to no avail.