Saigon (aka "Ho Chi Minh City") is a city - the capital of the southern region of Vietnam. It's the southern trade hub. There's no real farming going on here. For farming, you go down into the delta, where the alluvial soil is a major boon for all types of farming. Since cinnamon is bark of a tree I would think it would grow at a higher altitude. In the southern highlands there is Dalat - a lovely mountain town with TONS of agriculture, and an agriculture university, and the famous annual "Dalat Flower Festival" (which I'm sure your fine lady would much enjoy). What's nice about Dalat is that the cool (often downright COLD) whether there makes more people hang out in the cafes, drinking coffee, and reading. Vietnam is famous for its coffee, but the colder weather adds to the whole coffee experience, with more of the steam coming out, etc. You know, that NorthEast (America) vibe during the cold months (but not nearly as cold). But it seems that cinnamon agriculture may be more focused in the north of the country, from this article:

https://vietnamnews.vn/english-through-the-news/535743/cinnamon-the-spice-of-life-for-farmers.html

Anyways, all sort of herbs and spices are big here in Vietnam. That's one thing the Vietnamese do right.