QUESTION: What is the real meaning of the question:

ANSWER: The speaker is asking about the other person's experience (the exact time of the visit is not relevant). The speaker wants to know more about the knowledge and experience of that person to better understand who they are (in present time). They are not interested in when the person went there.

In Diagram 2, you can see how an experience in the past affects the knowledge of a person in the present.

In this sense, you can think of the Present Perfect being used to connect the Past with its consequences in the Present. In Diagram 2, this act of connecting the past action with the present context is the Reference Point (R) for the Present Perfect:

When the Present Perfect is used, it is focusing on the outcome of the experience, rather than on the details of the past event. You would talk about your experience and knowledge  - I have seen the Taj Mahal. It is beautiful....

If on the other hand, you used the Past Simple and said, I saw the Taj Mahal, you would be talking about a completed action that happened in the past. You would be talking about your visit, rather than your experience.  Extra information would centre around when you saw it, who you went with, why you went there etc. This information is all in the Past Simple. 

It is important to note that the Present Perfect is used in unspecified time. It is not possible to say I have been there last year (WRONG). Either you say I have been there, or I went there last year.

Present Perfect with FOR and SINCE

One of the most constant rules in the English language is that if you see the words FOR or SINCE, you know that the sentence must be in Present Perfect:

• I have been here for three years.
• I have studied English since I was 12 years old.

This is because for and since connect the beginning of the event with Present time.