The Health District in my view is bounded by:

I-95 to the East

Dolphin Expressway to the South

NW 14th Ave to the West

NW 20th St to the North

Properties within these boundaries are limited/rare, so while the above is the 'actual area' I also mean the surrounding neighborhoods and streets.

The area doesn't have the best reputation in terms of safety (Though there are definitely rougher areas in the city), but it does seem like it a solid rental market - with plenty of jobs nearby.

It is also fairly close (Depending on traffic) to Wynwood, Downtown, and Little Havana/stadium(s) and the airport.  Again good not only for entertainment but also for workers/jobs. 

I'm wondering what people's thoughts are on the area, both as a rental market/cash flow, but also the chances of gaining some appreciation there if/when things improve there.

It does look like there are some relatively reasonably priced (In terms of the average cost in Miami these days) properties for sale there - both single family and multi-family. I haven't really calculated things out or focused on any particular properties but it seems like it could be an area worth considering?