The Nether

The Nether is one of the three realms in the Minecraft universe (The others being the Overworld and the End.) and acts as the game's Hell dimension (or rather, in 2b2t's case, one of the three hell dimensions). It is accessed by using a Nether portal, which are generally seen around spawn abandoned or disabled. Because one block length in the Nether is eight blocks in the overworld, many players generally flock to the Nether's highways as a main source of travel.

-Spawn
Like the overworld and End spawn, the Nether spawn does not always stay the same and is constantly changing as players pass through. The spawn of the 2b2t's Nether is an immense chasm of ever-changing floating bridges and pillars of various blocks that is completely obliterated from the bedrock roof to the bedrock floor. The bottom is filled with several lava lakes and has a thriving population of withers on the bedrock surface. The vast majority of activity and development occurs just beneath the roof, because tunnels built at the top of the nether cannot be flooded with lava from above. A large platform made mostly from obsidian is usually located at the middle of the nether spawn, which periodically gets damaged, repaired and added on to by various players and groups. Players can almost always be found hanging out here, either to kill other players that try to pass through, or to control the area so they can do what they want with it. Usually both.

-Highways
Four highways extend outwards along the x and z axes towards the world border. Closer to spawn, they are very large tunnels with elevated platforms made from a wide variety of different block types, mostly obsidian, running through them. This is due to players using explosives and creating withers within them, which has widened them over the years. For most of their regularly traveled lengths, they are 2 blocks wide and 3 blocks tall, just the right size to ride a horse through. Very, very far out, they become only 1 block wide and 2 blocks tall, so players need to go on foot or ride a pig or boat instead. All of the 4 highways reach the world border, thanks to the good work done by the Diggers. A tunnel that extends 30,000,000 blocks through the nether to the nether world border has yet to be built, but a few have ventured out over 10,000,00 blocks, like R2bEEaton and Jordanl666.

-Uses
The Nether is an ideal place for people who want to travel due to the Minecraft mechanic where one block in the Nether equates to eight blocks in the overworld. Portals to the nether are also used for gold farms, in which players create large Nether portals in order for zombie pigmen to emerge from them and fall into a machine that kills them. It is also used for its regular Minecraft purposes such as mining or farming for soul sand, nether bricks, nether quartz, magma blocks, Ghast tears, Nether wart, Blaze rods, magma cream, and sometimes even for Netherrack. Wither skulls are not generally farmed for since they have been duped thousands of times and Wither Skeletons barely spawn, if at all, due to 2b2t's bad mob spawn rate. The Nether is also host to easy pickings against nakeds or unprepared travelers.

-Availability of Items
One of the main disadvantages of 2b2t's age is the difficulty of obtaining nether items. Because the server is so old and so thoroughly explored, you have to go really, really far out to find nether fortresses, which only generated after 1.0, and even farther out to find netherquartz, which only generated after 1.5. Naturally generated magma blocks, added in 1.10, are even harder to find, but fortunately, they can be crafted with magma cream, and generate naturally in the underwater trenches in the overworld [that will be] added in 1.13. Netherwart can be farmed anywhere and so is easily obtained, but blaze rods are a different story. And the low spawn rates of ghasts and magma cubes makes getting ghast tears and magma cream more difficult than normal (but not impossible). Of course, wither skulls are almost completely impossible to obtain, even more so than normal, and so players are better off getting them from someone else than trying to get them themselves.

-Issues
Not as many issues have arisen in the Nether as in the other two dimensions, however, issues have still arisen nonetheless. One of the most common and major issues that Hausemaster had to deal with over the years was access to the Nether roof. There have been several glitches, exploits, and hacked clients that have allowed players to access the top of the bedrock roof of the Nether over the years. Players would use the nether roof as a place to build stuff that would be inaccessible to most other players (including, in the early days, one of the first duping machines ever built on the server), and they would also use it to travel long distances through the nether very easily along the entirely flat and featureless bedrock ceiling, rather than having to go to the trouble of tunneling through the nether proper. However, this didn't last, as lagfags would abuse the flatness of the nether roof and use hacked clients to run extremely fast through the nether and load copious amounts of chunks very quickly in order to seriously lag the server. This eventually prompted Hausemaster to close the Nether's rooftop entirely by installing a plugin that would teleport anyone who got above level 127 back down below the roof.

Trivia

 * The nether receives plenty of traffic every day, especially along the main highways, because of how convenient it is for fast travel. The spawn in particular receives very heavy traffic, with it being a very common occurrence to encounter someone there. The "nether hub" is considered by many to be the most dangerous place on the server simply because it is the site of the most player activity (and because it overlies a 100+ block drop into a wither-infested magma-covered jagged floor of indestructible rock). Having max level gear and totems is obligatory if you are planning to spend some time at 0, 0 (without dieing).
 * Despite (or perhaps, because of) this traffic, not many people actually build in the Nether, and mostly prefer to build in the overworld (or occasionally the end).
 * If you (try to) sleep in a bed in the nether, a bed bomb will occur. This is one of the reasons the nether is more dangerous than the overworld, as beds can be used by suicide bombers, which are easily obtained and don't have to be placed on obsidian, as opposed to end crystals. However due to the fact that they can not stack, they are for a few uses only if the first explosion doesn't kill the bomber immediately.
 * There was a time in which players using elytra hacks would fly under the nether floor to travel rapidly through the nether, entering and exiting through holes in the bottom bedrock layer opened up through exploits or hacks. As long as players stuck close to the floor, they would not take void damage.
 * Several people used a boat phasing glitch to travel millions of blocks an hour through the Nether without needing highways. This allowed some to reach distances of up to 15,877,000 on the X+ axis (jordanl666), and 10,000,000 x 10,000,000 on the X+Z+ diagonal axis (R2bEEaton).