The Nether Hub is a room around the centre of the map (x = 0, y = 0) in the nether that was built and is maintained by the community led by Cassolotl. It is a central point - all roads in the Nether Network lead to the hub.
We haz them.
Since the Nether Network is so big now, and most of the useful bits are accessible by horse, players benefit from having a horse in the nether just for getting around.
The horse pen is designed such that a player can jump over the fence, and a horse and its rider can simply walk over the fence, but a horse without a rider can't walk out alone - and zombie pigmen can't walk in. It's also paved to prevent mob spawns, so it's a safe space to run to if the zombie pigmen get a bit pushy.
Informal junk yard
Following the dismantling of the junk yard at Zero Zero, Cassolotl threw down a few boxes with accompanying signs and item frames for easy navigation. Players drop off unwanted inventory items and pick up useful bits and pieces on a regular basis.
If you need a lot of netherrack, this is the place to go. If you want to build a megabow from many nearly broken enchanted bows, check it out. In a pinch you might find some food when your hunger bar is low.
A 3x3 room protected by glass and a wooden door with a pressure plate inside for speedy escapes. (Our game mode is such that zombie pigmen cannot break down wooden doors, even though it plays the breaking door animation.) It is paved with slabs to prevent spawns.
Posts made of coloured wool and signs lead the way to the coloured arches.
One day Cassolotl got whimsical, as sometimes happens, and made a button in the Nether Hub with their deity-powers. It's not easy to spot, but when you push it, you get surrounded by hearts.