Hay un muro de escalada.

Hay means there is or there are. It comes from the verb haber and is used to say that something exists.

So:

• Hay un muro de escalada = there is a climbing wall
• Hay dos muros de escalada = there are two climbing walls

Unlike English, Spanish uses the same form, hay, for both singular and plural.

Spanish uses hay to introduce something as existing, and está to say where a specific thing is.

Compare:

• Hay un muro de escalada en el gimnasio.
  There is a climbing wall in the gym.

• El muro de escalada está en el gimnasio.
  The climbing wall is in the gym.

So hay is for existence, while está is for location of something already identified.

Because muro is a masculine noun, so it takes the masculine indefinite article un.

A useful basic pattern is:

• nouns ending in -o are often masculine
• nouns ending in -a are often feminine

So:

• un muro
• una pared

That is why the sentence has un muro de escalada.

De escalada tells you what kind of wall it is. Literally, it is something like wall of climbing, but in natural English we say climbing wall.

This noun + de + noun pattern is very common in Spanish:

• gafas de sol = sunglasses
• mesa de comedor = dining table
• muro de escalada = climbing wall

So de escalada works like a classifier: it specifies the type of muro.

Both can make sense, but muro de escalada is the normal fixed expression for climbing wall.

• muro de escalada = the standard name
• muro para escalar = a wall for climbing

The second version is understandable, but it sounds more descriptive and less like the usual label. In everyday Spanish, muro de escalada is the more idiomatic choice.

In Spanish, when you have a type-expression like noun + de + noun, the second noun often appears without an article.

So you get:

• muro de escalada
• gafas de sol
• zapatos de deporte

Here, escalada is being used in a general sense, not referring to one specific climb or one specific instance of climbing.

If you said de la escalada, it would usually mean of the climbing in a more specific sense, which is not what this sentence needs.

Normally, no. In standard everyday Spanish, you would say Hay un muro de escalada.

Because muro is a countable noun, Spanish normally uses an article here:

• Hay un muro de escalada.
• Hay dos muros de escalada.

Without un, it sounds incomplete in most normal contexts. You might see article-dropping in very special styles such as headlines, labels, or notes, but not in ordinary speech.

No. Hay stays the same.

Examples:

• Hay un muro de escalada.
• Hay varios muros de escalada.
• Hay muchas personas allí.

This is important because English changes from there is to there are, but Spanish keeps hay for both.

The most neutral word order is:

• Hay + noun phrase

So:

• Hay un muro de escalada.

But Spanish also often moves a place phrase to the front:

• En el gimnasio hay un muro de escalada.

That is still completely natural. What is less natural is putting un muro de escalada before hay with no special reason.

A simple pronunciation guide is:

• hay = like eye
• un = roughly oon, but very short
• muro = MOO-ro
• de = deh
• escalada = es-ka-LA-da

So the whole sentence sounds roughly like:

eye oon MOO-ro deh es-ka-LA-da

A couple of useful notes:

• the h in hay is silent
• the r in muro is a single tap, not a strong rolled rr

Yes, depending on what exactly you mean.

• muro de escalada = climbing wall
• pared de escalada = also possible, often similar in meaning
• rocódromo = often a climbing wall facility or climbing gym area, not just the wall itself

In Spain, rocódromo is very common. But it is not always exactly the same as muro de escalada. A rocódromo can refer to the whole installation, while muro focuses more on the wall itself.