Certain caves have a particular fascination for those people which have a belief in finding the treasure in them.
1. Grammatically, this sentence is in error since the relative pronoun which always refers to inanimate objects and cannot correctly be used to refer to people as is done in the sentence above. Therfore, which should be changed to who
In addition to this error, there is another minor one. Although in many languages such as the Romance languages, nouns must be preceded by an article such as the or a or an, the article is not used in English when a noun is used in a general sense as is the noun treasure. Therefore, eliminating the is advised.
2. Stylistically, the relative clause could use some revision which would improve the clarity of the sentence. While there are different ways to rewrite this clause, here are a couple of suggestions:
a) Certain caves have a particular fascination for people who believe these caves contain treasure.
b) Certain caves have a particular fascination for people who believe there is treasure in them.
The advantage of using (a) is that
- the pronoun them has been eliminated, thus removing an ambiguity. For, the use of nouns over pronouns is preferable in communication as pronouns sometimes are unclear as to their antecedents.
- Also, the relative clause has been shorted and made more succinct for better communication, as well.
(b) has made the relative clause more concise and a bit stronger in meaning, using believe as the predicate rather than the verb have.
In addition to the wonderful grammatical explanations of mwestwood above, please consider whether or not you want to poetically personify certain caves. Caves don't have fascination. Fascination is a state of mind experienced by sentient beings. Certain caves may evoke fascination or be fascinating to people.