Opalescent Bridge

The opalescent bridges were a miracle of magitech invented and maintained by the combined efforts of the gnomish engineers of Cruor and the mages of the Isle of Shining Glass. They were a form of portal large enough to march a small army through, and completely by accident, were powerful enough to circumvent both the curse on the oceans of Lastlock and the astral plane around it.

Functioning
It was well known that the bridges functioned by using the power stored in magical crystals inside a series of complex machinery. The mages enchanted the crystals and the gnomes maintained the machinery. Though stepping through the bridge feels like instantaneous transport to someone traveling through it, there is actually a delay of several minutes between entering the portal and exiting on the other side. During this time, the creature traveling exists only as part of the transit and experiences nothing.

Though the gates typically needed receivers at both ends to function, it eventually became clear that it was possible to create extremely short lived one way gates, directed to somewhere the user was familiar with. However, the repeated use of such gates would result in confusion and sickness by the user.

Known Examples
Central-Northern: The bridge connecting the central and northern continent connected the outskirts of Cruor to the tip of the central continent. It stood until the Battle of the Bridge, when it was destroyed by Zael'drasa to slaughter the Tyradorian army inside and separate the 9 masters from the rest of the army. The bridge was not rebuilt until several years after the end of the Second Aeon War.

Southern-Central: The southern gate stood without being destroyed since its creation, though it began to wear thin and require maintenance by the end of the Second Aeon War. Early in the War, the southern gate was diverted to briefly connect to the northern continent, as a means of swiftly reuniting J.J. Jingleheimer with his son.

Central-Isle: The gate to the Isle of Shining Glass was destroyed by Calax, using the army created with the Heart of the Mountain. This triggered the mages being unable to help the rest of the world, as they were attacked shortly after by the Sard.

Bilabad's Gate: Bilabad created an extremely temporary gate to Keystone Island, while a prisoner of and using the experiences of Jackson Aberdeen. The pair of them traveled there and stole the Keystone, after which point Bilabad escaped back through the portal just as it was disintegrating, causing him to be randomly displaced.

Aeon Falls: The Tainted Reality kidnapped and dominated a series of engineers and mages and had them construct him a modified bridge, powerful enough to escape Lastlock and send him back to his homeworld of Aeon World. During this escape, Ash, Tophlyn, Bilabad, and Taggart were caught in the portal and transported with him. The portal was later repaired by the same engineers and mages who built it, and was briefly captured by Zael'drasa, who intended to use it to escape, and then by Veshike, intending the same, before finally being used along with the corpse of the archangel Rafael to help Veracion, Veshike, Niok, and Clarisse travel to Heaven.

Eastern-Central: Some years after the end of the second aeon war, the eastern continent was finally connected to the others via opalescent bridge, though they remained mostly isolationist after being hunted for years by the Bogeyman.