Samaria was a city of great wealth built by the warlord Omri (1 Kings 16:24) on a hill three hundred feet above the plain. This was then surrounded by higher hills. Amos imagines the powerful foreigners looking into Samaria from these hills with disgust and disbelief.1
9 Proclaim to the strongholds in Ashdod and to the strongholds in the land of Egypt, and say, “Assemble yourselves on the mountains of Samaria, and see the great tumults within her, and the oppressed in her midst.”