projecting tableland or mountain
塙 centers on a raised, projecting landform: a tableland or a mountain that juts out prominently.
塙 combines 土 (earth) with 高 (high), suggesting a high earthen feature such as a projecting tableland or mountain.
The left side is earth 土, and the right side is high 高. Picture a high, flat-topped mountain of earth rising above the surrounding land.
For カク, imagine a hawk (カク sounds like hawk) perched on the high projecting tableland, surveying the earth below.