I had a suggestion of an asylum come up from a friend. 

Merits: 
Most people avoid.
Would not have been used for disaster relief. 
Designed to provide security and protection
Plenty of food stores
Likely to have backup power
Infirmary, medication, sanitation, some recreation facilities
Usually good sight lines, decent kill zone, sturdy construction, good positioning for rooftop coverage. 

Flaws:
funnels, tight spaces
designed to prevent egress/escape/evasion
not self-sustained or contained
no permanent off-grid solutions
may still have patients to take care of/watch out for
May have former patient and faculty walkers within the facility and may take a while to fully clear. 

Thoughts?