Here are some thoughts on post-apocalypse living options. I'll talk about location, structure, and defense mechanisms for your living options.
CITY = BAD
RURAL = GOOD
OK, that's Survival 101. Now time for more advanced stuff...
FORESTS, MOUNTAINS, PLAINS, and TROPICS are all good places to try and survive. It's hard to say which is the best choice. Most likely you'll just go to whatever is closest to you. You can hide and survive in any of these places as long as you are remote enough. These places are the best choices, because they provide the best combination of ability to produce food, while at the same time remaining remote and hidden.
COASTAL regions can provide some great sources of food, but you will be much more likely to come across other people. 70% of the world's population currently lives at the ocean. Obtaining fresh water might be a problem. If you go to a location where fresh water is near the ocean, you are even more likely to run into people. Generally speaking, the further inland you go, the more scattered and available fresh water is. The closer you get to the coast, the more likely fresh water is to have already formed large rivers. Coastal regions are not the best option, but if you can find a remote stretch of coast, it can work out...or if you are the type of person who says, "Give me seafood or give me death!"
Let's talk about EXTREME PLACES. Above, you see the Amazon rainforest, very remote British Columbia, Wood Buffalo National Park in Canada, a desert, and a swamp. If you are crazy enough to survive in any of these locations, no one is crazy enough to bother you there. Look at the Amazon...don't tell me it's not possible to disappear in a place like that and never be bothered by anyone. If you can get past all the creepy crawlies and avoid the various forms of poison, you can carve out a nice little piece of paradise for yourself. By relocating to a location such as one of these, you'll successfully trade in one set of problems for another set of problems. You won't have human problems, but you'll have nature problems. Instead of Man vs Man, it will be Man vs Nature (and possibly Man vs Self :) ) It's your survival prerogative.
How about ISLANDS? If the island is large enough to sustain you and there is a source of fresh water, islands can be a wonderful bug out location. Make sure they are uninhabited or very sparsely populated and they don't have a bridge to them. Most people won't have access to a plane or boat after society collapses. If you have that access and you can get there, you might want to go for it. Being surrounded by a body of water is basically the best defense. If people can't get to you, then there's nothing to worry about. The first island shown is Santa Cruz. I consider it and its neighbor, Santa Rosa, to be the best bug out locations in Southern California. If you go with a smaller island, like the others, you can successfully keep watch and make sure no one ever comes onshore. The other three are Crater Lake in Oregon, South Twin Island in Lake Superior, and Dry Tortugas off Key West. If you had about 100 people and serious firepower on Dry Tortugas, nobody could ever take your position. Look at that thing...it would be an awesome bugout location!
CAVES and OLD MINES: The good thing about them is they can help with protecting you from the elements. You might also find secret places inside to hide. However, there is a risk of cave-ins, poisonous gas, low oxygen levels, and smoke inhalation. Plus, random people wandering by might want to investigate. It's not worth it to me.
OIL RIGS: I'm not joking when I say that I consider these to be a serious option. There are over 3,000 offshore oil rigs in the Gulf of Mexico alone. You are isolated and don't have to worry about people bothering you. If people are coming, you'll be able to see them from far away. You're defense will be more solid than mountain tops or cliff dwellings! I honestly can't think of a location that would have better defense. It's like a giant moat around you. Look at the one on the top. Who could attack you on that thing?? Nobody. That's who. The cons are getting freshwater, importing soil to grow gardens, and finding something to burn. These are big issues.
Speaking of ocean, what about the idea of living on a SAILBOAT? Similar to with the oil rig, your defenses can be good since you can have a moat that is miles wide. Gas will run out at some point, so unless somebody has a faster sailboat, nobody will bother you at sea. However, you will likely be coming ashore somewhere for supplies or to hunt or forage or whatever. Your canned food will run out at some point. What about storms? What about malfunctions on the boat? If something happens to you out at sea, you're dead. There won't be a coast guard crew to come help you. If you do go for this option, I recommend having a plan to settle on an uninhabited island at some point. You might as well chart out the 100 best looking uninhabited islands. Have a plan A-Z. A sailboat can give you flexibility and allow you to sail for a few months in safety before you find a nice island to settle.
Speaking of being mobile, what about living in MOBILE VEHICLES? A nice RV or tricked out bus could work well, because you don't have to construct your lodging once you get to where you're going. Staying mobile can be a great advantage as well. If there is danger, being able to leave in a few seconds is a fabulous option. However, even if you can get gas, your vehicle won't work forever. Eventually, it will just be a couple rooms on flat tires. Having a large vehicle is good for bugging out, but you wouldn't want to stay on the move during the chaos. It will be dangerous. Your best bet will be to find a solitary place in the wild and settle in. Keep your vehicle camoflauged. If you have a few vehicles in your group, remember the concept of circling your wagons.
CASTLES: When I saw Snow White & The Huntsman recently, I thought to myself, "dang, that would be a tough castle to seige." In many ways, we are going to be thrown back into the feudal system. There is a reason castles were used all over the world--they work! Live inside and put up big ass walls around you. Also, store your food and valuable possessions inside. They have a similar problem to the mountaintops and cliffs in that you will most likely have to grow and graze outside the walls. You could always build a wall around your gardens as a first line of defense and then retreat to your castle walls as the last line of defense. I think castle type walls will be used by the good guys, but not so much at first. At first, it will be about surviving with small groups. After about 10 years, the good guys will form alliances and begin to re-establish cities with big walls for defense. The bad guys will have already done this. I doubt we will ever go through a phase of building full-scale castles, because I think within 100 years, we will return to modern civilization and there just won't be enough time to build structures that take 50 years to build, but cities with big walls--definitely.
HOUSE WITH A MOAT: Hey, if it helps with your defense, consider if it will work in your situation. I wouldn't want to live in any of these 3 houses, because they are pre-existing structures, which means there are populated areas nearby or there are at least roads leading to these places, which can mean trouble. However, once I get to my bug out location, I would see if it's possible to dig a moat.
GORD: This historical slavic village fort has ramparts, usually walls and a gate in a circular design to protect the people within. It's simple enough that it could be entirely constructed post-collapse. You can live inside and it will also hide and protect your goods from people on the outside. Just a tip though, a square design works better, so visibility of the attackers is better and the walls can be better covered. I like this concept very much.
STOCKADE: Stockades are small villages completely surrounded by palisades (pole walls). The early American colonies were built with this design. If you were to use such a design, you would need a walkway near the top on the inside or just have a rampart on the inside that allows your armed men to be in position at the top. The other alternative to a walkway or rampart would be to build multiple guard towers. Overall, I think stockades are a little too much work for the amount of effectiveness they provide.
MILITARY OUTPOSTS provide great defense and unlike castles, they are geared toward modern warfare (small arms fire, etc.). They obviously have great defense and quick setup, which is basically what you'll need in a SHTF WROL scenario. Once you get to your bug out location, put yourself in the shoes of a military officer who has the task of securing your base from the worst threats possible. We can learn from military outposts.
At first, a lot of people will be living in TENTS. When this is happening it will be the worst of times. Water stops flowing to homes, so people move to nearby bodies of water and live in their tents. Then people begin to starve. When people begin to starve, they get desperate and steal and kill. The smart bad guys will realize there is no end in sight and there is no help coming, so they will turn to a life of gang banging/war lordism/evil militias. They will systematically sweep areas, kill, steal, and rape. Tent massacres will be a common thing. Buuut, if you are very far from humans, there's nothing wrong with living in tents for a while as you construct your permanent living situation. I would just recommend camoflauging it and using one that you can see out of in all directions.
LOG CABINS have been used for centuries. They are fairly easy structures to construct on the frontier (or in the wilderness in a bugout location). They don't require a lot of special tools, equipment, machinery, or materials. It's basically logs and mud. If it works for you, go for it, but try to keep it hidden as much as possible.
ADOBE HOUSES (mud brick houses) are from the international concept of using local materials for construction. Mostly seen in the American southwest and Mexico, they regulate temperature well and can be somewhat camoflauged. If it works for you, go for it, but keep it hidden as much as possible.
TEE PEES: When it comes to survival, it's always worthwhile to consider how the natives did it. Many of the plains Indians lived in tee pees. I think it had something to do with not a lot of trees around. But I also know it had to do with the ability to drag your tee pees to a new location and set them up easily. They were nomadic, so this was important. In a survival situation, you won't be nomadic most likely. Tee pees also stick out in the landscape. They're not very incognito.
LIVE UNDERGROUND. I really like this option. You are hidden. The temperature is regulated. If you don't mind a little dirt, this is a great option. You also want to situate it so that your living quarters don't get flooded.
VIKING HOME/EARTHEN ROOF: This living option is good for the same reasons as living underground. It's just a little more visible, but a little more user friendly.
SHIPPING CONTAINERS: For shipping containers below ground, see bomb shelters below or living underground above. Here, I'm commenting on shipping containers above ground. They are solid, strong, waterproof structures. They provide better defense than tents, tee pees, and maybe some of the other structures. However, if not camoflauged, they will stick out like a sore thumb. They also can get hot during the day if not properly ventilated, so they are not as good at regulating temperature as other structures. However, they are cheaper than a house and quicker to set up than a log cabin or adobe house. Another problem is that the moving crew will see your bug out location, but you can always make up a lie.
Ah yes, BOMB SHELTERS, the gem of preppers. Super safe from outside attacks and bombs. If they are set up correctly, you can live in them for as long as you've stored up food and water. Now do you want to know the real deal about these things? They're not worth it. Are you really going to live in this small thing? Ever heard of cabin fever? What happens when you run out of food and you haven't been up on the surface growing more? It will stink like crazy down there. You won't have good vision outside. People can smoke you out. If you get trapped in there, you won't have any place to retreat to, you're stuck. Eh, it can be incorporated into your bugout location as a safe room or storage unit, but it's not a golden solution. I'd rather fight like a lion on the surface than hide like a meerkat underground. But if you are expecting a nuclear bomb to be dropped nearby, then get one for sure.
ABANDONED MILITARY BUNKERS can still offer great defenses. That's what they were built for. However, people will often be aware of where they are. There's no guarantee that others won't try to live in them. The entrances are often visible. Not the worst idea, but not the best. I'd rank them as a little better than caves and mine shafts.
MISSILE SILOS are basically one really big survival bunker. These have the same pros and cons as the bomb shelters, except instead of just dealing with your family's issues, now you have to deal with issues of the 50 strangers that are living with you too. No thanks.
URBAN BUILDINGS are the worst idea. It's dangerous. You don't have access to clean water or food. Large areas of cities will burn to the ground because there will be no firefighters to put them out. Basically...you're gonna die if you stay there.
SUBURBAN HOMES are better than the inner city, but they are not a good option either. If there are 1,000 or more people who live in your area, don't even consider staying in your location. You'll be OK for longer than someone living in the inner city, but eventually the chaos will get to you as well. Are you prepared to turn away starving neighbors? Then, once warlords and gangs form, they will sweep through neighborhoods and go from house to house taking what they need. You might be able to hold them off, but is it worth the risk and the paranoia?
RANCH HOUSES/RURAL HOMES: OK, we're getting warmer. This particular ranch house looks like a good one. It has good outward visibility and a nice wall from behind which you can shoot at the bad guys. However, people from miles around will be able to see this house. They might be starving and desperate. If you opt for a ranch house or rural home, I would want it to be at least a mile from any paved road and as far away from population centers as possible. Then, be prepared to defend your home, because there's a good chance you'll have to.
CAMPING IN THE WOODS: Unless I have hundreds of thousands of dollars to buy land and prepare a bug out location, camping in the woods of a large park would be my choice. You can survive and stay hidden while all the chaos rages in other places. If you go to a place that is isolated enough, you won't have to be paranoid all the time of people coming to steal from you. You might be lucky enough to never have someone stumble upon your campground. Just make sure to not camp out near a large body of water. Camp near a small stream that flows year-round. The other thing about bugging out to remote locations is that you are more likely to find others in these locations who are self-sustainable go-getters. In other words, they are the type of people who are less likely to steal from you. They've decided to strike out on their own and try to live by the sweat on their brow just like you. Those are great people to form alliances with.