Many museums and historical sites are mainly visited by tourists but not local people.

I think "rather than" would better illustrate the contrast, but this would sound fine to the average native speaker.

There are a number of factors that can help to explain why these places lose their primary appeal to locals.

Perhaps the primary reason is that not only historical sites but anylso things in general gradually loses their primary attraction for humans.

The noun-verb agreement is awkward since both the singular and plural don't sound right, so I would rephrase. "Anything" by itself also doesn't read well.

These places are much more exposed to local inhabitants so thatLocal inhabitants are exposed to these places much more, so it is natural that locals doare not attracted to them the same way as foreign visitors are.

"So that" introduces purpose; "so" itself is fine as a conjunction.
Generally, the wording is "someone is exposed to something."

The more similarity between the cultural background of a historical place and a visitor, the less attractive that place to the visitor.

Another reason might be that authorities often do not pay enough attention to conserve the historical places.

Or "these/those historical places." (We haven't really specified a certain group. "These" or "those" might be acceptable in that it would at least refer to the sites described earlier in the passage.)

To gain back residents’ interest, the authorities can rearrange and redecorate these tourist attractions to make them more absorbenticing to the visitors.

The original was grammatical, but "absorbing" isn't really an adjective that I associate with places.

I wouldn't use the definite article with "visitors" because we are discussing visitors in general, rather than a specific group. Alternatively, you could say "local visitors" or the such if you wanted to be more specific.

The authorities can continue campaigning, aiming at increasing the public awareness public of these attractions.

In summary, enough good measures can be taken in attracting the local inhabitants.

"Enough" sounds incomplete here: I would expect a clause set off by "that" afterwards. ("Enough good measures can be taken in attracting local inhabitants, that they may visit such sites frequently.")

hHistorical p Places

I think the correct term here is "historic places" but later on when you say "historical places" in the middle of the sentence it seems fine to me. I would be interested to see what other people think

The morgreater the similarity between the cultural background of a historical place and a visitor, the less attractive that place to the visitor.

The comma is necessary here for clarity, otherwise it can be confusing

The authorities can continue campaigning aiming at increasing theto increase public awareness public of these attractions.