Learn Hardcore Spanish (Latin America): La ciudad antigua está protegida por una muralla que rodea la colina central. - The old city is protected by a wall that surrounds the central hill.

In Spanish, most descriptive adjectives follow the noun they modify. Putting antigua after ciudad emphasizes it as a descriptive quality (“the ancient city”). If you put it before (una antigua ciudad), it can sound more poetic or suggest “former city,” so the post‐nominal position is the neutral, descriptive one.

What is the function of está protegida por? Is this a passive construction?

Yes, está protegida is a passive‐voice construction formed with estar + past participle (protegida). It describes the current state of the city (“is protected”). The agent that does the protecting follows introduced by por (“by a wall”).

Why do we use por here and not de or para?

In Spanish passive sentences, the agent is introduced with por (“protected by a wall”). De would indicate origin or material, and para would indicate purpose or destination. Only por correctly marks who or what performs the action in a passive construction.

What does que rodea mean, and why is que used?

Que is a relative pronoun meaning “that” or “which.” It introduces a relative clause describing muralla. Rodea is the present‐tense verb “it surrounds.” So una muralla que rodea la colina central = “a wall that surrounds the central hill.”

Why is central after colina rather than before it?

Like most adjectives, central follows the noun colina to describe its characteristic (“the hill in the center”). Placing central before colina (la central colina) would be unusual or poetic and might shift the nuance.

Could we say la ciudad vieja instead of la ciudad antigua? What’s the difference?

Both can mean “old city,” but there’s a subtle nuance: antigua often implies historical or ancient significance, while vieja simply means “old” without that historic flavor. Here, antigua fits because we’re talking about an ancient, historical city.

Why is protegida feminine singular, and why does it agree with ciudad?

The past participle protegida must agree in gender and number with the noun it describes in a passive construction with estar. Ciudad is feminine singular, so we use protegida (feminine singular).

What’s the difference between muralla and muro? Why choose muralla here?

Muralla refers to a defensive wall, usually thick and surrounding a place (like city walls). Muro is a more general word for any wall (inside a building or dividing properties). Since this is about a protective wall around a city, muralla is the precise term.