Có một hồ gần khu cắm trại.

Here, có means there is / there are. It is not the have meaning of có.

So Có một hồ... literally works like There is a lake...

This is a very common Vietnamese pattern for introducing something:

• Có + noun phrase
• Có một quán cà phê gần đây. = There is a café nearby.

Một literally means one, but in many sentences it also works like a / an.

So một hồ means a lake or one lake, depending on context. In this sentence, it usually just introduces an indefinite noun, so English naturally translates it as a lake.

You may also hear Có hồ gần khu cắm trại, without một. That sounds more general, like There is a lake near the campsite without emphasizing the number. Adding một makes it feel a bit more like introducing one particular lake.

Vietnamese does not need a dummy subject like English there.

English says:

• There is a lake...

Vietnamese simply says:

• Có một hồ...

So the existential idea is carried by có itself. This is very normal in Vietnamese grammar.

Both một hồ and một cái hồ can be acceptable, depending on style and context.

• một hồ is concise and natural, especially in neutral or written-style Vietnamese.
• một cái hồ is also natural in everyday speech, with cái acting as a general classifier for an object/thing.

So:

• Có một hồ gần khu cắm trại.
• Có một cái hồ gần khu cắm trại.

Both can mean the same thing. Learners often expect a classifier every time, but in real Vietnamese, classifiers are sometimes omitted.

Gần means near or close to.

In this sentence, gần khu cắm trại means near the campsite / camping area.

Vietnamese often places location words like this after the noun:

• một hồ gần khu cắm trại = a lake near the campsite

So the structure is:

• noun + gần + place

Examples:

• một nhà gần trường = a house near the school
• một quán gần công viên = a shop near the park

Not necessarily. The sentence is natural as written:

• Có một hồ gần khu cắm trại.

You can also say:

• Có một hồ ở gần khu cắm trại.

Adding ở can make the location phrase feel a little more explicit, but it is often optional in sentences like this.

So both are natural:

• gần khu cắm trại
• ở gần khu cắm trại

Khu cắm trại literally means something like camping area.

Breakdown:

• khu = area, zone
• cắm trại = to camp / camping

So khu cắm trại can be translated as:

• campsite
• camping area
• campground

The best English choice depends on context.

In Vietnamese, the general noun often comes first, and the describing element comes after it.

So:

• khu = area
• cắm trại = camping

Together:

• khu cắm trại = camping area

This is a very common Vietnamese pattern:

• trường học = school (learning school in literal order)
• xe đạp = bicycle (pedal vehicle)
• khu vui chơi = play area / amusement area

So Vietnamese often builds noun phrases in a different order from English.

Vietnamese often does not mark definiteness as clearly as English does.

So khu cắm trại could mean:

• the campsite
• a campsite
• the camping area

Context tells you which one is intended.

If the listener already knows which campsite is being discussed, English may translate it as the campsite. If it is new information, English might use a campsite.

Usually hồ means lake or a fairly large pond/reservoir-like body of water. In many learning contexts, lake is the best translation.

Vietnamese has several water-related words, for example:

• hồ = lake
• ao = pond
• sông = river

So hồ is larger than ao in the usual sense. If you translate hồ as lake here, that is the most natural choice.

Yes, it is natural.

Some close alternatives are:

• Có một cái hồ gần khu cắm trại.
• Có hồ gần khu cắm trại.
• Có một hồ ở gần khu cắm trại.

The differences are small:

• cái adds a classifier
• omitting một makes it more general
• adding ở makes the location phrase more explicit

But the original sentence is perfectly normal and clear:

• Có một hồ gần khu cắm trại.