She quickly felt conspicuous as the sun began to fall behind the hills.
They've set up behind the hills, and it looks like we're in for a few shells.
Laurie looked to the west, where the sun set behind the hills.
The sun was down behind the hills now, and darkness filled the middle of the room.
None had moved from their basic positions before and behind the hills.
The sun was dropping behind the hills before they were ready.
By the time dinner was over, the sun had dropped behind the hills.
The sun was now low behind the hills on the right: the valley before them should be in total darkness.
I kept my closed eyes on the sun, which would soon be gone behind the hills.
With the sun behind the hills, the temperature has dropped.