ぼんち盆地bonchi
1.

A flat or gently sloping area of land that is surrounded by higher elevations, such as mountains or hills, creating a depression in the landscape.

2.

A low-lying geographical region that is enclosed by higher terrain, often formed through geological processes such as faulting or erosion.

3.

A depressional landform characterized by its level surface, completely encircled by elevated landforms, making it distinct from the adjacent higher ground.

Example:

河川の盆地には普通肥沃な農地がある。