Explain how 向{む}く "to face" can take "上{うえ}" as a direct object using を?


There's a famous old song that's actually the only ever Japanese language song
to reach #1 on the US pop charts: "上{うえ}を向{む}いて歩{ある}こう".

This is both the title of the song and a frequently repeated line in it.

向{む}いて is the -te form of 向{む}く, meaning "to face".

My understanding of 上{うえ} is that in Japanese it's a noun even though it's
usually translated to another part of speech in English, such as "up".

It seems odd from the point of view of an English speaker that "to face", "to
look toward" would be a transitive verb requiring a direct object.

Is that in fact what's happening or have I got it all wrong trying to parse
this phrase due to my English speaker's intuition and my limited knowledge of
Japanese?

Is what I'm seeing more of a quirk of the verb 向く or is there something about
the particle を that I haven't learned yet? Or maybe it's all about the 上 in
this case?




Although it is usually the transitive verb that takes a "Noun + を" in front of
it, there is an important exception to this general rule.

Intransitive verbs such as 向く、[走]{はし}る (to run)、[飛]{と}ぶ (to fly)、[出]{で}る (to
get out), etc. can take a "Noun + を" when it describes the place of an action
or the direction of a movement.

> 上を向く = to look upward
>
> [公園]{こうえん}を走る = to run in the park
>
> [空]{そら}を飛ぶ = to fly in the sky
>
> レストランを出る = to leave the restaurant

Other such intransitive verbs:

[曲]{ま}がる (to make a turn)、[降]{お}りる (to get off)、[通]{とお}る (to pass), etc.




Although it is usually the transitive verb that takes a "Noun + を" in front of
it, there is an important exception to this general rule.

Intransitive verbs such as 向く、[走]{はし}る (to run)、[飛]{と}ぶ (to fly)、[出]{で}る (to
get out), etc. can take a "Noun + を" when it describes the place of an action
or the direction of a movement.

> 上を向く = to look upward
>
> [公園]{こうえん}を走る = to run in the park
>
> [空]{そら}を飛ぶ = to fly in the sky
>
> レストランを出る = to leave the restaurant

Other such intransitive verbs:

[曲]{ま}がる (to make a turn)、[降]{お}りる (to get off)、[通]{とお}る (to pass), etc.

