Uptime Gate
The Uptime Gate was a powerful time corridor that connected the City of the Saved to the universe. In the City, it took the form of a mile-high block of stone situated in the Erstwhile Plaza in Central District. While open, it was often the site of reunions, partings, pageants, and expeditions. (PROSE: Of the City of the Saved...)
Though the term technically only applied to the terminus inside the City, it was generally used to refer to the other end as well. The in-universe end was situated on a mountain on a distant planet close to the frontier in time, so distant from the Wartime powers that the entire area almost existed in a state of truce. The area around the Uptime Gate became a posthuman settlement called Ascension. (PROSE: The Book of the War, Of the City of the Saved...)
The Gate was eventually closed. (PROSE: Of the City of the Saved...)