La salle d’escalade contient un mur d’escalade.

In French, after a noun, de + noun often shows the type, purpose, or function of something.

So:

• une salle d’escalade = a climbing room / climbing gym
• un mur d’escalade = a climbing wall

Here, escalade is being used to describe what kind of room and what kind of wall. In this structure, French usually does not use the article.

If you said de l’escalade, that would usually fit a different structure, such as:

• faire de l’escalade = to do climbing / to go climbing

So the difference is about grammar, not meaning alone.

Because de becomes d’ before a vowel sound.

• de + escalade → d’escalade

This is called elision. French does this a lot to make pronunciation smoother.

Other examples:

• de + eau → d’eau
• de + école → d’école

Literally, it is:

• salle = room, hall
• d’escalade = for climbing / of climbing

So word-for-word, it is something like room for climbing or climbing hall.

In natural English, depending on context, it could mean:

• climbing gym
• climbing room
• indoor climbing facility

Because both nouns need to be specified:

• salle by itself just means room/hall
• mur by itself just means wall

French repeats d’escalade to show:

• the room is for climbing
• the wall is a climbing wall

This is completely natural in French. French often keeps the full expression rather than avoiding repetition the way English sometimes does.

This is the difference between the definite and indefinite article.

• La salle d’escalade = the climbing gym / climbing room
• un mur d’escalade = a climbing wall

So the sentence is talking about:

• a specific or already-known climbing room: la salle
• one climbing wall inside it, not identified as a particular one: un mur

If you changed them, the meaning would shift:

• Une salle d’escalade contient un mur d’escalade = A climbing gym contains a climbing wall
• La salle d’escalade contient le mur d’escalade = The climbing gym contains the climbing wall

The original sentence is the most natural if you mean the climbing gym contains a climbing wall.

It is feminine.

The basic form is:

• l’escalade

You can see it clearly in sentences like:

• J’aime l’escalade. = I like climbing.
• L’escalade est difficile. = Climbing is difficult.

In d’escalade, the article is not shown, but the noun itself is still feminine.

Yes. Contient means contains, holds, or includes.

So:

• La salle d’escalade contient un mur d’escalade. = The climbing gym contains a climbing wall.

In everyday French, a is often more common:

• La salle d’escalade a un mur d’escalade.

That means basically The climbing gym has a climbing wall.

The difference is small:

• a = more everyday, simpler
• contient = slightly more formal or descriptive

Contient is the 3rd person singular present tense of contenir.

So it matches la salle, which is singular:

• la salle ... contient

A few forms of contenir are:

• je contiens
• tu contiens
• il/elle contient
• nous contenons
• vous contenez
• ils/elles contiennent

So in this sentence, contient means contains.

Yes, the final letters are not pronounced the way an English speaker might expect.

contient is pronounced approximately like kon-tyen, with a nasal ending.

More precisely:

• contient ≈ /kɔ̃.tjɛ̃/

Important points:

• the final t is not pronounced
• the ending is nasal
• it does not sound like English content

Also, in contient un, there is normally no liaison. So you do not pronounce a t between the words.

Because these are two different grammar patterns.

1. faire de l’escalade
   Here, de l’ is part of the verbal expression for doing an activity.
   It means to do climbing / to go climbing.

2. salle d’escalade / mur d’escalade
   Here, de links two nouns to show type or purpose.
   It means climbing room / climbing wall.

So even though both use escalade, the grammar is different:

• faire de l’escalade = activity
• salle d’escalade = category/type of place
• mur d’escalade = category/type of object

It can mean either, depending on context, but very often it refers to the whole indoor climbing facility.

Even though salle literally means room or hall, in real usage une salle de sport can mean a gym, and une salle d’escalade can mean a climbing gym.

So learners should not always translate salle too literally as only room. Sometimes it refers to a whole venue.