apart も far も使いません。
正しい英語は「The closest station is still 4 kms away」。
「Still」を入れた理由は、「でも」を表現するためです。
このような still の使い方は、以下の例を参考にしてください：
- The fastest time I could muster was still 2 seconds slower than the fastest runner（最善の努力を果たして一生懸命走ったが、それでも一番速い選手よりも２秒遅かった）
The example you gave works fine on it's own. You can also say the following as alternatives though there is not much difference between them.
"The station nearest to here is 4 kilometers away."Nearest is just an alternative word to "closest"
"There is a station 4 kilometers away from here"Again there is not much difference here,just a different way to say it.
あなたの考えた例でも問題ありません。それ以外に次のように言うこともできます（ただ、違いはあまりありません）。
"The station nearest to here is 4 kilometers away."（最寄りの駅は4キロ先です）
"Nearest" は "Closest"（最も近い）の別の言い方です。
"There is a station 4 kilometers away from here"（ここから4キロ先に駅があります）
これも、大した違いはありません。単に別の言い方というだけです。
"The closest station from here is 4 kilometers away."
"From here, the closest station is 4 kilometers away."
"The closest station is 4 kilometers away from here."
You gave a perfect example answer to your own question. I added two more examples of saying exactly the same thing. All words used in each of the three examples are exactly the same, but it is the word order or sentence structure (syntax) that differs. This shows how flexible the English language is. You say exactly the same thing in three different ways by using the exact same words.
You'll find the nearest station 4 km away from here.
Travel 4 km and you will find the station.
If you are giving someone directions it is great to give them estimates of distance.
"I think the grocery store is about 2 km from here, it isn't far at all."
'From here' means that you are measuring the distance starting from where you are at that moment.
"If you are looking for a meal, the closest drive-in is only 500 meters from here."
Estimate: a guess, roughly calculate
Nearest/closest: the one that you will see first, is not far away
道案内をするなら、だいたいどのくらいの距離なのか教えてあげるといいですね。
"I think the grocery store is about 2 km from here, it isn't far at all."（ここからそのスーパーまではだいたい2キロくらいだと思います）
'From here' は、それが現在地から距離であることを表します。
"If you are looking for a meal, the closest drive-in is only 500 meters from here."（食事をしたいなら、最寄りのドライブインは500メートル先です）
Estimate: 推測、だいたいの計算
Nearest/closest: 最も近い
The next station is 4 kilometers away. - This sentence can be used to express the distance of the nearest station from the current location.
The nearest station is 4 kilometers away. - This sentence can be used to express the distance of the nearest/closest station.
The next station is 4 kilometers away.（次の駅は4キロ先です）
この文は、そこから次の駅までの距離を表します。
The nearest station is 4 kilometers away.（最寄りの駅は4キロ先です）
この文は、最寄りの駅までの距離を表します。
The nearest station from here is 4 kilometers away.
The closest station is 4 kilometers away from here.
When trying to tell someone that the nearest station is 4 kilometers away, you can simply say " the nearest station is 4 kilometers from where we are now" or " the closest station is 4 kilometers away from here". The word "nearest" tells them that is is the fasters/closest station to their current location.
「最寄りの駅は4キロ先です」は、シンプルに次のように言えます。
"The nearest station is 4 kilometers from where we are now"（最寄りの駅はここから4キロ先です）
"The closest station is 4 kilometers away from here"（最寄りの駅はここから4キロ先です）
"nearest" は、それが現在地から「最も近い」駅であることを表します。
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