Dark Achievement City is a reverse version of the original Achievement City located in The Nether. The city was created when Geoff and Gavin decided to reset the Nether using a feature given in the latest update. This meant that the Nether Fortress could now be added to the normal Achievement City seed without making a new world. The city now resides on top of one of the Nether Fortresses and has a number of slight differences, and lots of major differences compared to the original, most notably the Achievement Hunter Logo being made of a combination of different Nether related materials. It first appeared in Let's Play Minecraft Episode 56. Geoff stated that it would be used in future Let's Plays that have not been revealed yet. (It is theorized that the future Let's Play Geoff was speaking of was to be Let's Play Minecraft - Episode 200. This is due to the items Jack received in Let's Play Minecraft - Episode 100 as a reward.)
- Gavin's House of Art and Dreams: Gavin's house is now made of a combination of moss stone and smooth stone. Gavin is missing a few paintings inside his house as well as his Trophy Room of Victories. Gavin stated that he found a Monster Spawner and did not want to destroy it.
- Michael's House: Remains the same as the original, except it is built out of a darker wood. One painting inside the house is different as Gavin said it was "close enough" to the original.
- Jack's Stilted Shack: Leaky Ceiling remains, but during construction Geoff and Gavin accidentally burned it down, and whilst trying to place blocks to stop it he slept in Jack's bed causing an explosion (Beds explode when using them in The Nether). There is also a sign that says "my mom loves me" in Jack's house. Like Michael's house, Jack's house is made from darker wood.
- Ryan's Kung-Fu House: Edgar the Cow is replaced by a villager, and the Chicken is replaced with an Egg in an Item Frame, the sign says "In Case Of Emergency, Break Egg".
- Geoff's Monolith: The house is built to the top of the Nether and is made out of Stone Bricks.
- Ray's Mud Hut: The house is made of Soul Sand, not dirt, and Slice of Hell is not functional. The dirt podium is Soul Sand as well. No roses were put into Ray's chests.
- The Logo: The logo is now a combination of Netherrack, Obsidian, Glowstone, and Netherbrick Blocks. Plan G was not installed in the construction of Dark Achievement City.
- Stone Bridge: The bridge is made of Nether brick with lava underneath instead of water.
- The concept of Dark Achievement City and the opposite contents (besides the buildings) is a common trope in media where an object/person/location has a polar opposite of the original. This is seen with many things in the Dark Achievement City being different from the original;
- The Obsidian podiums are upside-down, thus the entire Tower of Pimps will be seen upside down.
- Edgar the Cow and Ryan's chicken are now a Villager and an egg.
- Instead of Ray's trademark roses, Nether Wart is present.
- Gavin used the Nether Portal spawning system to his advantage causing the portal to spawn perfectly between the two Achievement Cities, much to the surprise of the rest of the team.
- Geoff and Gavin claimed that it took them seven hours to build Dark Achievement City. Geoff stated "when he thought they were done Gavin wanted to add something else." Geoff also said he might do a Let's Build for it. The Let's Build for Dark Achievement City ended up being 3 parts, the longest Let's Build at the time. It has since been surpassed by Ice Cube, which ended up being 5 parts total and several minutes longer.
- The five points on the star in the Achievement Hunter logo are lit on fire, correlating to the locations of torches in the original Achievement City.
- The Dark Achievement City Bulletin Board says; "Reading is Knowledge, Knowledge is Power, Power Kills, Kill Everything."
- During the construction of Jack's house, Geoff and Gavin burnt it down four times. Jack's original Achievement City house was also burnt down in the process.
- A tree resides in Dark Achievement City near Michael's house.