Yazın göl kenarında kamp yaptık.

Here, yazın means in the summer or during summer.

It comes from yaz = summer, but in this kind of expression Turkish uses a special adverb-like form for seasons:

• yazın = in summer
• kışın = in winter

So in this sentence, yazın tells us when the action happened.

For seasons, Turkish usually does not use the regular locative ending -da/-de the way English uses in.

So instead of yazda, Turkish normally says:

• yazın = in summer
• yaz mevsiminde = in the summer season
• yaz aylarında = in the summer months

So yazda would sound unnatural in standard Turkish for this meaning.

Göl kenarında means by the lake, at the lakeside, or more literally at the edge/side of the lake.

It breaks down like this:

• göl = lake
• kenar = edge, side
• göl kenarı = the lakeside / the side of the lake
• göl kenarında = at the lakeside / by the lake

So the phrase tells us where they camped.

This is because Turkish often forms compound nouns this way.

In göl kenarı:

• göl = lake
• kenar = side, edge
• kenarı = its side / the side of it

So göl kenarı literally means something like lake-side or the side of the lake.

This pattern is very common in Turkish:

• ev kapısı = house door / the door of the house
• okul bahçesi = school garden / the garden of the school
• göl kenarı = lakeside / the side of the lake

That -ı is part of the noun compound structure.

Because the base phrase is göl kenarı.

Then Turkish adds the locative ending -da/-de to mean at/on/in. But since kenarı already ends with a vowel-like possessive form, Turkish uses a buffer n before the case ending:

• göl kenarı = the lakeside
• göl kenarında = at the lakeside

So the structure is:

• göl kenarı
  • -nda

This n is very common after possessed forms before case endings.

They mean different locations:

• göl kenarında = by the lake / at the lakeside
• gölde = in the lake / on the lake

So:

• Yazın göl kenarında kamp yaptık. = We camped by the lake in summer.
• Gölde yüzdük. = We swam in the lake.

A learner might confuse them, but kenarında clearly means near the lake, not inside it.

Turkish often uses a noun + yapmak (to do / to make) for activities.

So:

• kamp yapmak = to camp
  literally: to do camping

Therefore:

• kamp yaptık = we camped

This is a very common pattern in Turkish. For example:

• spor yapmak = to do sports / exercise
• alışveriş yapmak = to shop / do shopping
• tatil yapmak = to go on holiday / take a vacation

So kamp yaptık is completely natural Turkish.

Yaptık comes from the verb yapmak = to do / to make.

It breaks down as:

• yap- = do, make
• -tı- = past tense
• -k = we

So:

• yaptık = we did

In this sentence, because the noun kamp comes before it, kamp yaptık means we camped.

Note that the root changes a little in spelling/pronunciation:

• yapmak
• yaptık

This is a normal sound change in Turkish.

It is built into the verb.

In Turkish, subject pronouns are often omitted because the verb ending already shows the subject.

Here:

• yaptık = we did

So there is no need to say biz.

You could say:

• Biz yazın göl kenarında kamp yaptık.

But biz would usually only be added for emphasis, such as we (not someone else).

Because Turkish normally puts the main verb at the end of the sentence.

So the pattern here is roughly:

• Yazın = time
• göl kenarında = place
• kamp = object/activity noun
• yaptık = verb

This verb-final order is one of the most important differences from English.

A very literal word-for-word order would be:

• In summer by-the-lake camping we-did.

Natural English changes the order, but Turkish usually keeps the verb last.

Yes, Turkish word order is flexible, but changing it changes the emphasis.

The neutral order here is:

• Yazın göl kenarında kamp yaptık.

You could also say:

• Göl kenarında yazın kamp yaptık.
• Kampı yazın göl kenarında yaptık.
  (with a slightly different structure and emphasis)

But the original sentence sounds very natural and straightforward: first when, then where, then the action.

It is a loanword, ultimately from a European source, but it is fully normal in modern Turkish.

In Turkish:

• kamp = camp / camping camp
• kamp yapmak = to camp

So even though it may not be originally Turkic, learners should treat it as an ordinary Turkish word.

A very literal translation is:

In summer, at the lakeside, we did camping.

But a natural English translation would be:

• We camped by the lake in summer.
• In the summer, we camped by the lake.

So the sentence means the same thing, but Turkish and English organize it differently.