Are there any mid-sized cities or tourist towns investors would recommend?

Heavy tourist towns would not make for a good LTR property. 

I'd say the economic level rapidly declines as you move inland pretty much anywhere.Some tourist towns in the mountains would be Boone, Blowing Rock, Asheville.  

With an estimated 2 million visitors annually, Annapolis ranks as one of the top tourist destinations in North America.

Kansas City is not a big tourist destination but they get 35M visitors a year that spend $1.4B on lodging.

I love my investment property in North Lake Tahoe, but even in this tourist area, there is tricky regulation. 

Snowmobile is a niche community but its gain popularity with tourists for rentals. 

I studied this extensively when I was providing input to the Town re: the STR Homestay program in 2015/2016; let's call a hotel institutional lodging - a community needs a certain percentage of available institutional lodging, per capita, in order to have a viable tourist/short-term stay ecosystem.

Pool Homes always rent best, especially now when many other options for tourist activities may be limited.We have software which allows us to analyze by community and create projections for each home based on projected occupancy.

Eventually I plan to place this home on the short term rental market, it is located in south florida right off turnpike, near the airport and beach, main roads and downtown tourist attractions. the area is going through a ton of gentrification so I plan to hold on to this one for at least 5-10 years.