It's a common expression indicating a location above the speaker or a general direction upwards.
Here are some examples of how it's used:
* "Le soleil est la haut." (The sun is up there.)
* "Il y a un oiseau la haut." (There's a bird up there.)
* "J'ai vu un avion la haut." (I saw a plane up there.)
The exact meaning of "la haut" can depend on the context. It can refer to a specific location, like the sky or the top of a mountain, or it can be used more figuratively, like to talk about a higher social class or a spiritual realm.