the skies above a certain place; (aviation) airspace; (Tw) topless
上 (shǎng) · 3 strokes
Originally a small line or dot above a longer line, indicating "up". The vertical line was added to distinguish the character from 二 (two). Opposite of 下.
空 (kōng) · 8 strokes
Phonosemantic compound. 穴 represents the meaning and 工 represents the sound.