Of course, we know how safe havens turn out in the world of The Walking Dead (and, really, why wouldn't Rick and the others? That's just sloppy). So...Season Five will begin with our group at Terminus, alright.
...Trapped in a boxcar, waiting to be killed and possibly eaten by people and/or zombies.
One of the first "mysteries" we solved about Terminus was that, based on the railroad map marking out its location, its real-world location would be Macon, Georgia.
In the Telltale Games series, a heavily fictionalized version of Macon (which is treated as a small town rather than a large suburb/small city, which is what it really is) is a major setting in the game, but other than that, the locale hasn't played much of a role in The Walking Dead...and we don't particularly expect it to in the future since...
Terminus is ACTUALLY just outside Atlanta, and historically the word is tied to that city.
The location where they film the Terminus scenes is actually not far from where they filmed the pilot in Atlanta. The skyline and topography around the building have been digitally altered to remove recognizable landmarks and the city skyline behind it in some angles.
Terminus -- literally "the end of the line" -- was originally the home to a settlement that would eventually become Atlanta in the state of Georgia.
The inhabitants are [almost certainly] cannibals
It's long been assumed that the Terminants may be a remix of The Hunters from the comic book source material, but during the Season Four finale, piles of apparently-human remains tipped their hand. Will they be eating the meat themselves? Feeding it to walkers? Something else entirely? We probably won't know for sure until the season opener, but given comments that Gareth will be "a remix" of existing characters and the fact that Mary feels a lot like one of the cannibals from the Telltale Games stories, we'd bet money on them being cannibals.
Terminus has been operation almost since the start of the outbreak
I wouldn't trust anything Gareth and Alex had to say, so the fact that it was Alex who gave the survivors their Terminus history lesson made it automatically suspect...but then one of the producers reiterated it during a "making-of" featurette -- someplace that it seems kind of pointless to lie.
It looks like a creepy altar, but they call it "The Church." That's where you can find the names and belongings of members of their community who have died.
“And this right here is Church. It’s kind of a memorial to our departed Terminants,” said Andrew J. West, who plays Gareth.
The names on the floor, then, are presumed to be the loved ones of the residents of Terminus, which presumably explains why there are trinkets left behind for them while the residents of the community are fairly shameless about pillaging from the living, taking things like Glenn’s pocketwatch and Eugene’s riot gear.
They have a history, and we will learn more soon
“There’s a big story to Terminus,” series creator Robert Kirkman explained in the finale's postmortem. “There’s a very long and involved way that Terminus came about, and that memorial is a big part of it. It’s what these people have lived through and what’s happened to them and what’s built them into what they are, which will be revealed in Season 5. There are a lot of hints when you watch this episode closely of what’s to come in Season 5, so I would definitely urge everyone to watch this episode multiple times and try to pick out the things we’re teasing because there’s a lot to find.”
It's not that they've got what's obviously an obstacle course set up, or that they had snipers on the rooftops and waiting in the trees, or that they had box cars full of screaming people. The Terminants clearly have done this before because JUST LOOK AT ALL THOSE BULLET HOLES IN EVERYTHING.
They have multiple different "routes"/traps they run their victims through
Is this for people who are more or less armed? More or less dangerous? Just when a certain box car is full? When Gareth shouted to "Get them off B!" and make sure they got to boxcar A, we were immediately curious.
It appears they were betrayed in the past
At the church, the writing on the wall cautions them to never forget, and never trust anyone -- that the community comes first, always. Certainly that sounds like they were betrayed by someone they trust. More than that, many fans have speculated that perhaps at one point Terminus was on the level -- that they really were trying to create a sanctuary before somebody came along and ruined it (probably by killing those remembere in the Church).
In a photo released by AMC, a deleted scene shows Rick, Carl, Michonne and Daryl dodging a string of chained-up walkers with piles of meat in front of them. This is presumably just part of the "obstacle course" that leads new victims to their boxcar, but it certainly raises all sorts of questions.
In all likelihood, the signs for Terminus are fairly new.
All throughout the second half of the season, our survivors ran into others on the road who talked about Terminus, or ran into signs for Terminus. During the first half of the season, though, we know that there was a lot of scouting going on in the areas around the prison, with Daryl getting as far as the moonshine shack with Michonne at one point. They also took in numerous survivors they encountered.
What are the odds that ALL THOSE SIGNS WERE UP and ALL THOSE PEOPLE WERE TALKING ABOUT IT, but by dumb luck our survivors just never became aware? It's certainly possible, and this one will likely get us some snide comments below, but "possible" doesn't mean "likely."
Terminus Has Radio Broadcasting Ability
In “Isolation,” Daryl, Michonne, Bob and Tyreese are driving in search of medical supplies when they are startled by a voice on the radio. The voice says, “Sanctuary. Those who arrive survive.” While the name “Terminus” was not used in the broadcast, this is the same slogan that appears on the signs for Terminus. Obviously, Terminus must be a place where enough of its infrastructure is intact that they have radio broadcasting capability.