Base of Operation(s)

Having a base of operation(s) in an apocalyptic scenario, will put you weeks if not months ahead of the rest of people out there trying to survive. 

When it comes to base ops., you want to take some things into consideration. Most factors are based around location. Is my base visible to the public eye? Is my base well protected from the outside? Do I have a secure way to keep others out of my base if they find it? 

There are many other questions to ask. Most of them will be answered in an Urbanocalypse. 

When choosing a base, I suggest picking a place that is in an area that you wouldn't suspect as being a base, if you are just looking at it from passing by. I guess another way to put this, don't make your base obvious. You don't need a military compound with six foot high, cement walls covered in razor wire. 

Something underground would probably be best. If its down in the sewer system, it would be super easy to use a maze of sewer lines to help conceal your base of operations. You would also have several points of entry and exit. It would be easy to block off sewer lines and flood them if your base were to be compromised. So this could be both good for you and disadvantageous. 

Another idea would be to place it somewhere very high up. I'm not talking about mountains or hills, but sky scrapers. If you are emitting any light from within the center of the floor, or a room with no windows, you should be alright. It would be a simple task to take all that office furniture, and toss it down the stairwells and elevator shafts. This would make great blockades and keep most people out. You could also use the air shafts, elevator shafts and even knock holes in the dry wall to move around in stealth in needed. 

Apartment buildings and high rise condos would be good in this sense. Most buildings in large cities, have fire escapes. This would be a good point of entry into your base of operations. One way to do this is you can barricade the first floor, or the floor that is used for entering. Clear any trash cans or large objects from under the fire escape, so that others cannot use it to gain access. If there is a basement, you can use a window for a quick escape if needed.

Another good thing to take into consideration, is using traps. Now granted most traps built in an urban area, would need to be concealed pretty well from the naked eye. But it would be a great way to deter people from trying to raid your base.

There are tons of different ways to avoid detection. Find what works best for you and your base.