"벽장은 벽에 있어요."

Translation: The closet is in the wall.

[LiKenun]

That would explain the 벽 in 벽장!

[Jeong-JinL]

The closet is in the wall.
This is a really weird sentence in English. Did the wall swallow it? Is it like a Harry Potter wall?
Otherwise, it would be through the wall (still sounds really odd but makes technical sense), built into the wall, or part of the room (which might be what's implied). Oh, final option that I've never seen in a real life home but could imagine—The closet is set into the wall. (inset like an alcove with a hanger bar and some other features)
Does the Korean phrase sound sensible?

[Iron_Venema]

It's a reference since the word 벽장 has 벽 in it

[Jeong-JinL]

A reference?

[jlseymour3]

Yes, in English we would not say that unless it was hidden inside the wall in some fashion, like a priest hole in the bad old days in England.

[LYOYDr]

"There is a fitted wardrobe." or "The wardrobe is built into the wall". Assuming a closet is a wardrobe rather than a water closet in which case "the toilet is en-suite" would suffice.

[KookieBTSARMY101]

It could be a built in closet. Try looking it up :))

[TomTheSailor]

I'm not sure what your confusion is. All closets (in the sense of a place for storage) are in a wall. A closet is a recessed area for storage (hanging clothes, etc.). Most have doors.