Why do you assume it was abandoned?
My oldest fort was my previous one, and that was only around four years.
Twas short but sweet, the life of Bulwarkdwellings. It was the home of a couple heroes, the birthplace of a few astounding tales, and, being my second fort ever, a place I will always remember.
/drama
Anyway, here's the story of it's end. Let's see if I can craft an epic:
For the most part, everything had been running smoothly. I had nearly finished my grand statue garden, a huge room with statues of brass and slabs of marble lining the engraved walls,(I was planning to do the floor as well), the wildlife problem was getting under control, almost all the dwarves had decent furnished rooms, and construction of the burial chambers was well under way.
In my growing experience, I decided i was ready to finally take of the challenge of building a well. Unfortunately, it was this decision that likely led to the downfall of Bulwarkdwellings. I had dug out a room with a large hole several z-levels in the center to fill with water. It went down below the burial chambers, making it the deepest point in the fort.
I had also dug out a tunnel that would drain a murky pool into the room, and a long corridor leading to the outside that would drain the room in case of flooding, I planned to fill them with traps, but only managed to get the floodgates placed before the Ettin showed up.
I had never faced an Ettin before, so I was worried. As it slowly made its way down the hill, a vile force of darkness appeared. I've fended off sieges before, but this wasn't like any goblin siege I had faced, a huge force of mounts, goblins, trolls, and their law-giver, a demon twisted into the from of a lemur or something like that.
Freaking out slightly, I station my military at the floodgate blocking the corridor. If i remember correctly, the Ettin busted through the floodgate, and my military attacks.
They are beating, stabbing and shooting at her, she proves to be less of a threat than I thought, but she won't die. it stumbles out of the well room, down the hall, and into my stone stockpile, my military following. The corridor, unblocked and unguarded, gives an easy entrance for the goblins and their law-giver, they swarm in. My military, still attacking the Ettin, is ambushed by the goblins. Some of them are quite literally back stabbed, others put up a good fight, but eventually, they all fall. Even Ral and her dog, but that's a story for another time.
It is at this moment that I notice trolls have broken down my main gates as well, the ones that make it past the traps begin slaughtering everyone. Back in the well room, some trolls find it a good idea to break down the floodgate holding back the actual water, just as a goblin macelord and his squad are chilling next to the huge pit. through this whole ordeal, there was nothing more satisfying than watching that entire squad of goblins get flushed down that huge hole. About half of them drown, the ones that survive are very injured, including the macelord.
But fate turned against me once more, there was a long tunnel that lead beneath the burial chambers I had dug to get the miner out of the hole, and i had yet to wall it up, the injured goblins slowly made their way up to the burial chambers, which were built directly below the residential area, any dwarves hiding in their rooms were killed.
The remaining dwarves were burrowed in the food/booze storeroom below the food/booze production area, with goblins and the demon law-giver approaching from one side, and trolls from the other, I watched the remaining members of Newlight the Immortal Earthendweller get splattered across the food and drink pots. Thinking quickly, I order everyone to fill the ranks of the fallen military, the storeroom becomes a canvas of blood.
They fight well, taking down a couple enemies with them. But eventually, the siege leaves, and only a single dwarf remains. They destroyed almost everything, killed nearly everyone, and leave me with a single dwarf. I'm enraged, I order this final dwarf to pursue the law-giver, but he's too fast, they get away.
I see the trolls, lounging about in my once great dining hall, I figure I'm going to go out with one final attack. The dwarf, who is now mayor, charges forth. To my surprise, she actually does a pretty good job, shes punching, scratching and I actually begin think she might do this, then a troll becomes enraged. She is gored by its tusks, adding to her already severe injuries.
She stumbles toward them again, constantly falling over, and tears out one of their teeth, causing it to vomit. She is gored again. Now the trolls take the offensive, she tries to run, but she's in too much pain, she falls over, gets surrounded, and the fort dies with her.
To add insult to injury, upon checking the legends, I read that the Ettin was killed by a goblin's copper spear.
Kudos to anyone who actually manages to read the whole thing without getting bored halfway through.