The Great Gyssian Arch
There are four Great Arches on Aquanus. This is the Southern one.
The Eastern Great Arch leads to Earth. It's the only one thought to be active--that is, it's the only one where it's known that the space-time separating Aquanus and the universe it belongs to is occasionally breached, allowing people from Earth to travel to this side.
There is no record of the same occurring with the Great Southern Arch, also known as the Great Gyssian Arch; likewise, no activity has been recorded from the Great Northern Arch or the Great Western Arch.
In this view, we see the Eternitam leading to the Great Gyssian Arch, which fronts the awesome celestial king, Ammalinaeus. It looks small against the gas giant, but it too is tremendous, rising, like the others, fifty miles into the Aquanian sky.
The Gyss is a barren and desolate land, for the most part, offering many vistas like this one. It was from the Gyss that Necrolius Anaxagorius launched the tremendous navy that would help him invade and ultimately conquer all of Aquanus.
For reference, here is the Map of Aquanus. (Right-click: "Open in a new tab" to get full-sized view.)