World border

The world border is a semi-transparent wall that surrounds the Minecraft world. The border is 30 million blocks on all four sides, centered around Spawn. It was made so that players could not venture into glitched chunks. Back in the days, if you went 12 million blocks out, you would reach the Far Lands, glitched terrain that would make mountains that reached the skies, and infinitely long caves. Mobs also acted weird there, and if you went even further, you would fall through the terrain, and shading did not seem to work. However these Far Lands were eventually removed, and there is no evidence that they were ever generated on 2b2t.

Overworld
The history of the World Border is shrouded in mystery, as it was reached first sometime in 2011 through a backdoor. This is known due to the findings of chunks from 2011 at the -X Axis Highway. This might have been reached through popbob's or Acid1212's (supposed) backdoor. The modern World Border was first reached by Pyrobyte and iTristan through their backdoor on December 7th, 2013 on the +X axis. There they left some bedrock and two signs. They also teleported to the -X and -Z world borders but did not leave anything there.

+X: On March 26 2017, the X+ world border was reached by xxq, rasqi, MiningMinecraft, househousehouse1, and Auion. The final stretch of digging was streamed on twitch by xxq and later uploaded to YouTube. The base Point Nemo was founded at the world border and lasted less than a week. Point Nemo was griefed by Babbaj. After Point Nemo's grief, the X+ world border area was turned into "new spawn" by Nordic93, who made a giant lavacast wall, similar to his well known ones at spawn. This was the first world border in Minecraft history to be reached by digging.

After this event, many other groups such as the +Z Diggers and -X Diggers where formed to finish the Highways to the other borders.

-X: The -X Diggers reached the border on December 22nd, 2017. They made a giant Christmas tree as they arrived two days before Christmas, and later exchanged gifts with each other.

+Z: The +Z Diggers reach the border on June 9th, 2017. This was the only overworld border that had not been teleported too.

-Z: The -Z border was the only one to be reached by flying first before digging. The player gRiNdLoRd flew under the Nether floor to the border for 10 hours, reaching it on August 7th, 2017. The highway itself was later completed by the group Highland.

End
The End World Border was first reached by Armorsmith when he took a week to fly using packetfly, lagging the server during the journey. When he arrived, he created a base called Armorland at the world border corner.

Nether
In March 2020, 0x22, IronException, and l_amp visited all main axis and corner world borders in the Nether, using a teleportation exploit. The Nether world border was first reached via mining on the +X Highway by the Motorway Extension Gurus on May 12, 2021. Previous signs by IronException and l_amp were present at the border upon arrival. The 0z Way to the +X was completed by the +X Nether Border Diggers on June 22, 2021.