is "stand watch over" a phrase?

[iemmahu]

"A 15-foot bronze Superman, who stands watch over Market Street where all the action takes place, keeps watch as well."

Thought it was ungrammatical. Can anyone explain it? Many thanks.

 

[Susan612]

Yes, to stand watch over something/someone is to monitor or guard an area or person. In the military a soldier might be assigned to stand watch. Stand guard has a similar meaning.