Albert Barnes Commentary 1 Kings 21:1

"And it came to pass after these things, that Naboth the Jezreelite had a vineyard, which was in Jezreel, hard by the palace of Ahab king of Samaria." — 1 Kings 21:1 (ASV)

A vineyard ... in Jezreel — The name Jezreel is applied in Scripture not merely to the town (1 Kings 18:46) but also to the valley or plain which lies below it, between Mount Gilboa and Little Hermon (2 Samuel 2:9; 2 Kings 9:10; Hosea 1:5; etc.).

The palace of Ahab at Jezreel was on the eastern side of the city, looking toward the Jordan down the valley described above. It abutted on the town wall (2 Kings 9:30–31). Immediately below it was a dry moat. Beyond, in the valley, either adjoining the moat or, at any rate, at no great distance, was the plot of ground belonging to Naboth (2 Kings 9:21).