Porto is a booming tech hub with increasing tourism and still cheaper than lisbon.

Do not feel a rush to get in right now as tourism is down. 

If a local economy relies heavily on tourism, a pandemic exactly like COVID or even a natural disaster, can greatly jeopardize the stability of the employment markets.

In the Viet Nam War days the only thing you could study was Law or Medicine.

Since you bought that first lot, the peso has declined significantly more compared to the USD so doing that again makes sense.While property prices have been going up strongly in Colombia due to the great economy, rising middle class and exploding tourism, prices are dropping for Americans because of the fall of the peso.Like everywhere, there are several ways to make money in the market.

Someone who is more pragmatic.Once the virus goes away tourism will come back.

I know tourism is still be there because of the Smokies, but are there other things that have been contributing to the home value growth over the last 10 years or so?

When tourism picks back up get an accessory permit and STR the other side.

Overall, pretty investor friendly with some exceptions like most areas, but the tourism & hospitality industries are huge down here which is why it has always been a great market for STR investors. 

We're home to 4 military installations (Lackland, Randolph, Fort Sam Houston, Camp Bullis), which provides a steady supply of quality, recession-resistant renters.There are also many investors that have found success with STRs in San Antonio as a result of the steady tourism.