Visitors to Actun Tunichil Muknal, a cave in Belize that serves archaeological site has to swim to its entrance

Visitors to Actun Tunichil Muknal, a cave in Belize that serves as an archaeological site, have to swim to its entrance.

Explanation:

The sentence has four mistakes:

It is missing a comma at the end of the relative clause. Without it, the sentence does not make sense. The word has that follows is referring to the archeological site, which grammatically is the correct verb for a singular person, but semantically it does not make sense.When we add the comma to clarify that "a cave in Belize that serves as an archaeological site" is extra information about Actun Tunichil Muknal, the verb has must be in the plural form (have) since it is referring to visitors.The clause "a cave in Belize that serves archaeological site" has missing words. First, the adverb as to signify that the cave equals an archeological site. Secondly, the indefinite article "an" The indefinite article means that Actun Tunichil Muknal belongs to the group of archeological sites.The last mistake is the closing punctuation at the end of the sentence.

The answer would be logical.