First, longan. Longan has a slightly peculiar shape, but a very good taste. It has a sweet flavor and is often used in desserts and drinks. Longan is in full bloom from September to November every year, when you can easily find very fresh longan in the market.
Second, persimmons. Underneath its orange-red exterior, the persimmon has a delightfully sweet flavor. It can be eaten raw, finished off to make preserves or other snacks, and used to make jam. It's in season in October and November and is available at most markets and farm stores.
Third, green plums. The flavor of green plums is similar to that of limes and clementines, with some subtle tartness, but still relatively sweet. It is often eaten as a snack or appetizer. You can buy fresh green plums during the season in May and June.
These are just one of the many delicious Vietnamese fruits. Whether you are traveling in Vietnam or living there, you should try the local fruits!