Apartment building-apartment buildings are filled with food, water, and other necessary supplies, not to mention phones, tvs, and radios. you could even go on the roof or in the basement and hideout. of course theres always the possibility that there are some infected in there but they can be taken care of. woods and mountains are outside and provide no shelter or cover. mountains might be ok for a while but not for more than a few days. a gas station isnt protected. its a good place to get supplies but not a good place to hide out. its covered in glass that can easily be broken through (unless its lined with bars) but youre gonna have loads of people coming there for supplies.