北京工人体育场

• ⼔(person turning back; figure of person from behind)ASSOCIATIVE

Two people standing back-to-back represent North, the direction ancients faced away from.

• 人(person; human (pictographic))ASSOCIATIVE

The character 人 depicts a person standing with legs spread wide apart for stability.

• 土(earth; soil; land)RADICAL
• 勿(don't; must not)PHONETIC

A wide field of land sounds similar to the word for things or objects.