It never hyperinflated the gold standard and had to change it back into a fiat to spend on the Vietnam War, contributing to the double digit inflation in the 1970s.

Even during Vietnam war when bodies of soldiers were brought home in huge numbers, most of the people were not affected.

My father owned tourism based businesses, and liquidated a few years ago, his contacts got him onto a group who buy property management rights, they offered him a buy in to the next property, a resort on the Gold Coast (one of the most popular tourist destinations in Australia), this investment (which was thoroughly looked over by his accountant and lawyer) over the past 3 years has been netting him on average 18% per year, passively.

There is probably a niche market there (and maybe a lucrative one for the right person and situation) but I quit doing seasonals in my area early in my landlording career.In my area, 3-4 month rentals are in demand in some time frames during the year (summer tourism, legislative session e.g.), but having done a few short term rentals early on, it just did not pencil out well for me. 

Costa Rica does make a good portion of their income from tourism so there is some effect going on.

Does anyone here have any resources or places for me to go to for learning about rental property investments in Vietnam?

I have direct relationship with a big manufacturing company in Vietnam which build containers and container homes and trying to have my first project in container homes in the US (Seattle areas where i live) as well.I believe this is very doable and profitable but there are few hard parts that requires you are doing your homework as a first container homes projects (besides other part like find funding etc.)1.

For that reason alone I wouldn’t touch anything that is not in a big city (Madrid, Barcelona, Sevilla, Bilbao), where I expect people to still relocate looking for better jobs, or in a nice area of the coastline, where you can count on either good tourism or well-off retirees.However, I believe there are opportunities in some neighborhoods and niches.

Is it in an area with vacationer appeal and steady tourism - you mentioned a beach was close by.  

Well, let this ex Marine, Viet Nam Vet, single dad, who went from unemployment to owning 16 single family rental homes and 28 multi family properties in less than 4 years, while attending college to obtain not one but two bachelor degrees while raising two young children tell you my reaction.