‘There’ is a noun.

In English, ‘there’ is an adverb. In Chinese, ‘there’ can be a noun. Or at any rate, can be analyzed as one.

那儿很热吗?
Nàr hěn rè ma?
There very hot [question particle]?
Is it hot there?

Same with ‘here’.

是的。 这儿很热。
Shì de. Zhèr hěn rè.
Is [particle]. Here very hot.
Yes. It’s hot here.

If that isn’t proof enough, then observe that you can apply the possessive to ‘here’ and ‘there’.

这儿的菜很好吃。
Zhèr de cài hěn hǎo chī.
Here’s dishes very good eat.
The food here is delicious.

I am not sure whether ‘hǎo chī’ is considered a word or a phrase. I don’t think it matters.

If you translate zhè li and nà li as ‘this place’ and ‘that place’, they make perfect sense as nouns. Then you have to account for the fact that these phrases are used without prepositions as if they were adverbs and not nouns.

他在那里。
zài nà li.
He is [located] that place.
He’s there.

But in fact  is not a noun meaning ‘place’. It is a noun that means ‘in’ or ‘inside’, or it’s the preposition ‘in’. So ‘zhè li‘ is ‘this inside’ and ‘na li’ is ‘that inside’.