Agartha

The myths are true. Among them is the old legend of the Hollow Earth, but not in the way most expect. The realm is called Agartha, and is a land of sourceless light shining down from a massive tree which stretches in all directions to infinity, following only whatever unknowable natural force that allows it to reach to new places and times. The Hollow Earth is a path between space and time, allowing travel to specific points across the world, and potentially throughout various time periods, though there is an absolute limit. Time is divided into sections called Ages, and a person from one Age cannot travel through Agartha to another Age, either future or past.

Agartha is maintained by massive, powerful, mute golems known as Custodians. They ensure that order is kept within the Hollow World (even from the Conspiracies), and ensure everything runs as it should. Anything causing damage to Agartha is subject to be quickly pummelled by these massive and dangerous constructs. And if they can't handle it? Well, that's when they call in the big guns of /every Anima Wielder on the planet/ via The Buzzing.

As Agartha stretches across space and time, it is the point that has connected to the Multiverse. The Warpgate that has naturally formed there is large enough for a small vehicle or perhaps a motorcycle, but one should be cautious about such activities in Agartha, lest the Custodians decide it needs to be removed. The natives all simply walk along the branches, using distortions in space to quickly rush along them towards the points of the branches that connect to other places in the world.

Additionally, Agartha, as an otherworldly location, is not entirely safe. Non-Elites should not be exposed to Agartha, as their nature is often unsuited to continued existence there, and they rapidly begin to lose coherence. Elites are resistant to this effect, but probably shouldn't stick around long regardless. Only the natives and those who have had their Anima tuned to the world are resistant to this effect (which can fairly easily be simulated by those who have the magical or technological knowledge to do so; this is mostly here to inform people that taking normal people through Agartha is a Bad Idea).