До озера около километра, поэтому мы дошли туда пешком.

До озера means as far as the lake / to the lake in terms of distance remaining. In this sentence, the speaker is stating how far it is: До озера около километра = It’s about a kilometer to the lake.

К озеру usually means toward the lake or to the lake as a direction of movement, not as a distance expression.

So compare:

• До озера около километра. = The lake is about a kilometer away.
• Мы пошли к озеру. = We went toward the lake.

Because the preposition до always takes the genitive.

The dictionary form is озеро. Its genitive singular is озера.

So:

• озеро = lake
• до озера = to the lake / as far as the lake

This is a fixed grammar rule: до + genitive.

Yes, in a way. Russian often omits есть or another form of to be in the present tense.

So the sentence literally feels like:

• До озера около километра (есть).

In natural English, that becomes:

• It’s about a kilometer to the lake.

Russian very often uses this kind of verbless sentence in the present tense.

Because около can mean about / approximately, and it normally requires the genitive.

So:

• километр = nominative
• километра = genitive singular

That gives:

• около километра = about a kilometer

This is the same pattern as:

• около часа = about an hour
• около дома = near the house

So около is a word learners should remember as one that usually triggers the genitive.

Here it means about / approximately.

Около has two common meanings:

1. near

   • около дома = near the house

2. about / approximately

   • около километра = about a kilometer

In this sentence, since около is followed by a measure of distance, it clearly means approximately.

Because after approximate quantities like this, Russian often uses the genitive singular after numbers ending in one or after expressions like около when the quantity is one unit.

Here the meaning is about one kilometer, so километра is correct.

Compare:

• один километр = one kilometer
• около километра = about a kilometer

If the number were different, the form might change:

• около двух километров = about two kilometers
• около пяти километров = about five kilometers

Because дошли means reached / made it there on foot, while шли just means were walking / went on foot without focusing on arrival.

• шли = were going, were walking
• дошли = got there by walking, reached the destination

In this sentence, the result matters: they actually arrived at the lake. So дошли is the natural choice.

The prefix до- often adds the idea of reaching a point or making it as far as something.

So:

• идти / шли = to go, to be going on foot
• дойти / дошли = to get to, to reach on foot

That matches the first half of the sentence, which talks about the distance to the lake. Then the second half says they made it there on foot.

Because туда means to there / there as a destination, while там means there as a location.

Since the verb дошли expresses movement to a destination, туда is the right choice.

• туда = to there
• там = there

So:

• мы дошли туда = we got there
• мы были там = we were there

Yes, absolutely.

• мы дошли туда пешком = we got there on foot
• мы дошли до озера пешком = we got to the lake on foot

Both are natural.
Using туда avoids repeating озера, since the destination has already been mentioned in the first clause.

Пешком means on foot. It is an adverbial form historically connected with the instrumental case, and learners usually just memorize it as a fixed word meaning on foot.

So:

• идти пешком = to go on foot
• дойти пешком = to get there on foot

Russian uses this one word where English uses the phrase on foot.

Поэтому means therefore / so / that’s why.

It connects the two ideas:

• It was only about a kilometer to the lake,
• so we walked there.

It often appears at the beginning of the second clause, as it does here:

• ..., поэтому мы дошли туда пешком.

That word order is very natural.

Yes, it could be omitted, because Russian verb endings often already show the subject.

• дошли already tells you it is we.

So both are possible:

• ..., поэтому мы дошли туда пешком.
• ..., поэтому дошли туда пешком.

Including мы makes the subject explicit and can sound slightly clearer or more neutral. Omitting it is also very common in Russian.

Yes, Russian word order is fairly flexible, though some versions sound more natural than others.

The original sentence is very natural:

• До озера около километра, поэтому мы дошли туда пешком.

Possible variations include:

• До озера около километра, поэтому дошли туда пешком.
• До озера было около километра, поэтому мы пошли пешком.
• Поскольку до озера было около километра, мы дошли туда пешком.

But the original is especially good because it is compact and natural in everyday Russian.