level ground
- flatLacking vertical variation
- plainBasic and unremarkable
- plateauFlat highland area
- terrainLand's physical features
- surfaceOutermost boundary layer
even · smooth · horizon · prairie · meadow · field · baseline · foundation · footing · steady · balanced · equal · flush · uniform · graded · flattened · surveyed · bulldozed
topographical gradient
level groundincline
Angled rising surface
slope · hillside · steep slope · steep terrain · gradient
surface regularity
level grounduneven ground
Irregular, non-flat surface
rough terrain · rugged terrain · rocky ground · rolling hills