Cerca del acantilado había un faro antiguo desde el que se veía casi toda la costa.

Because cerca is normally followed by the preposition de.

• cerca de = near
• lejos de = far from

So:

• cerca del acantilado = near the cliff

And del is simply de + el.

You generally cannot say cerca el acantilado in standard Spanish.

Del is the contraction of de + el.

• de + el acantilado → del acantilado

This contraction is required in Spanish, except with proper names or titles where el is part of the name.

So here:

• cerca del acantilado = near the cliff

Había is the imperfect form of haber, and here it means there was / there used to be.

Spanish often uses the imperfect to describe background, setting, or existence in the past:

• Cerca del acantilado había un faro antiguo... = Near the cliff there was an old lighthouse...

This sounds like scene-setting description.

If you used hubo, it would sound more like a completed event:

• Hubo un faro... would not fit as naturally here, because a lighthouse is not something that suddenly "happened" in the same way an event does.

So había is used because the sentence is describing a place and what existed there.

Because había agrees with what immediately follows it as an existential structure: un faro antiguo.

The core structure is:

• había un faro antiguo = there was an old lighthouse

The rest:

• desde el que se veía casi toda la costa

is extra information describing the lighthouse.

So the main thing that existed was one lighthouse, which is singular.

Both are possible, but they are not exactly the same.

• un faro antiguo usually means an old lighthouse in a literal/descriptive sense
• un antiguo faro can mean a former lighthouse or sometimes give a more literary/stylistic tone

In this sentence, antiguo after the noun is the most straightforward way to say the lighthouse was old.

Adjective position in Spanish often changes nuance:

• after the noun = more objective/classifying
• before the noun = often more subjective, emphatic, or with a shifted meaning

So un faro antiguo is the natural choice here.

Desde el que means from which.

It refers back to el faro:

• un faro antiguo desde el que... = an old lighthouse from which...

Breakdown:

• desde = from
• el que = which / the one that

So:

• desde el que se veía casi toda la costa = from which almost the whole coast could be seen

This is a relative structure linking the second part of the sentence back to faro.

Because desde que usually means since or from the time when, not from which.

Compare:

• desde que llegué = since I arrived
• el faro desde el que se veía la costa = the lighthouse from which the coast could be seen

Here we need a relative pronoun referring to faro, so Spanish uses:

• desde + el que

not plain desde que.

Both can sometimes work in similar contexts, but desde el que is more precise here because it clearly refers to the lighthouse as the place/source of the view.

• desde el que se veía... = from which one could see...
• desde donde se veía... = from where one could see...

Desde donde is also possible in many contexts, but desde el que directly matches the noun faro and is a very common relative construction after a preposition.

Because the antecedent is a masculine singular noun (faro), Spanish uses:

• desde el que

This is often taught as the safer grammatical pattern after prepositions.

Here se veía is an impersonal/passive-like construction meaning something like:

• one could see
• you could see
• almost the whole coast was visible

So:

• desde el que se veía casi toda la costa = from which almost the whole coast could be seen

This se does not mean himself/herself/itself here. It is being used to avoid naming a specific person who was doing the seeing.

Spanish often uses this structure when English uses:

• you could see...
• one could see...
• ...could be seen

Without se, veía would normally need a subject:

• Juan veía la costa = Juan could see / saw the coast

But in this sentence, no person is mentioned. The idea is general and impersonal:

• from the lighthouse, almost the whole coast could be seen

So Spanish uses se veía to express that general idea without saying who was seeing it.

Because the imperfect veía fits a descriptive background scene.

The sentence is not talking about a single moment when someone suddenly saw the coast. It is describing a continuing characteristic of the lighthouse:

• from there, almost the whole coast was visible / could be seen

The imperfect is common for:

• descriptions
• habitual situations
• background information
• ongoing states

So se veía works much better than se vio here.

Because que here is a relative pronoun, not an interrogative or exclamative word.

Spanish uses accents on words like qué, cuál, quién, cuándo, dónde when they are used in questions or exclamations, direct or indirect.

Here, que simply links back to faro:

• el que = which / that

So it has no accent.

Because toda here modifies the noun phrase la costa:

• toda la costa = the whole coast / all the coast

In Spanish, with this meaning, the article is normally kept:

• todo el día = the whole day
• toda la noche = the whole night
• toda la ciudad = the whole city
• toda la costa = the whole coast

Toda costa by itself is not correct with this meaning.

It means almost the whole coast or nearly the entire coastline.

Breakdown:

• casi = almost
• toda la costa = the whole coast

So the sentence suggests the view was very wide, but not absolutely complete.

Spanish is flexible with word order, especially in descriptive sentences.

Starting with Cerca del acantilado puts the location first, which helps set the scene:

• Cerca del acantilado había un faro antiguo... = Near the cliff there was an old lighthouse...

You could also say:

• Había un faro antiguo cerca del acantilado...

That is also grammatical, but it places the existence of the lighthouse first rather than the location.

The original version sounds very natural for narration or description.

Yes. Because había is imperfect, both can be possible depending on context.

• there was = neutral past description
• there used to be = emphasizes that it existed in the past, perhaps not now

Without more context, there was is the safest literal choice. But used to be can also fit if the wider context suggests the lighthouse no longer exists or no longer serves that function.

Either can work.

• was visible focuses on the state
• could be seen focuses on the possibility of seeing it

In this sentence, could be seen is often the most natural English rendering:

• from which almost the whole coast could be seen

But from which almost the whole coast was visible is also a very good interpretation.

The basic meaning is cliff.

• acantilado = cliff, especially a steep coastal rock face

In this sentence, cliff is the most direct translation.

Cliffside is more of an English adaptation depending on the context, but it is not the literal core meaning of acantilado.