an earthwork / castle / position of defense / stronghold / used in place names, often as phonetic bao for "burg" or "bad"
堡
=
保
+
土
:
Beelzebub (b) created a new olace for his valuables. Inside of the aorta (ao3) he built a sand castle (堡). In the center of the castle (堡) there is a heap of clay (土) on which a safe (保) is resting.