Answer:
It comes across to me that you come from a “hierarchy” culture where one would formally address an elder with respect. Here it is your uncle, whom I assume is an older gentleman, probably your parents’ older relative, living in a rural area with limited or no modern means of communication near by where he lives. Writing would be the next best thing. I would be happy to get a letter in the mail from my near and dear one who lives in another country.
I would start by saying,
Respected Uncle or Dearest Uncle….,
I hope you are doing well.
It has been a long time since we have seen each other. I remember my childhood when mummy and papa would bring us sometimes on our holidays to spend time with you. It was one of my best holdisays, and I want to visit again with mummy and my family so they too can have an experience of rural sunny life in ……..
I have not been out of the country (name your country) for some time now as I was tied down with some personal work at home and also my job kept me busy.
Now that I am able to free up some time, I thought about coming to visit you for a few weeks. First, mum was wanting to spend some quality time with you before she gets older and would not be able to travel later on alone; and second, since it is winter out here, this would be an opportune time to enjoy your sunny weather and be with you.
Uncle, I am mailing this letter to you today and we are all eagerly waiting to hear back from you soon, so we can make necessary travel arrangements.
Your nephew,
