Hill
You have a scene going on inside your head. It is of a pair of horns on the ground atop a mountain. No. It is not just one pair of horns. It is many. So many that they create a giant hill atop the mountain, which is already pretty high.
こう
おか
None
How was standing atop this hill of horns on top of a mountain to touch the sky? Eh. It was okay (おか), but that's about it.