One of the five realms in the Elements family, Gatherall is unique in not being a quadrant of the Earth that was isolated by the activation of the Barriers to end the Pulse War. Gatherall is still isolated by a forcefield, but this one was created in a different way.
Gatherall's Place Among the Elements Realms
At the end of the Pulse War, three prophets came out of the Wilderlands, collecting followers along the way. Together, they led many of the survivors to the coast, and then across the Pacific Ocean till they arrived at a chain of islands - Hawaii. There, they proved themselves to the faithful by performing a miracle - erecting a Barrier that was powered by pure faith rather than Pulse. A 10km sphere, part island, part ocean, was enclosed and purified by the divine power of the Trinity, as the three prophets had become known, and their followers set about creating a new civilization inside, a grand city, safe from the horrors outside.
The city soon found a name - Gatherall. There were people from all walks of life, and the new society was soon blossoming. They had everything they needed, apart from power. And that's when the prophets performed their second great miracle, reactivating the giant Pulse node on the island, which had been drained of all power by the machines which created the other Barriers. As a result, life in Gatherall continued at much the same technological level as before, with little of the former knowledge lost. Outside, meanwhile, those who hadn't followed the prophets found survival very difficult amid the post-apocalyptic wastelands, different enough that each is considered a different Suzerain realm.
Gatherall retains a 'cyberpunk' level of technology, approximately a hundred years ahead of technology in the real world now. Computing has largely moved on from silicon-based processors (silitech) to celestium-based computers. Nanotech and biotech are the two new frontiers of development.
That said, the greatest restraint on Gatherall is space. There's a forcefield, a 10km sphere, and outside is the toxic remains of the post-War world. 150 million people live inside that space; crammed into 300 storey-tall skyscrapers that almost touch the top of the Barrier. Even the ground by the coast has been hollowed out (the excavated earth used as a building material for the skyscrapers above), and the huge cavern is full of floating platforms with communities living on them. And off the coast there are sub-sea colonies and sky islands above the waves. Literally every space possible has been used with barely enough room to fly a hover vehicle without hitting something - hence why they're restricted to the authorities and millionaires while everybody else has to use traditional vehicles on the spaghetti of elevated roadways clinging to the sides of the skyscrapers.
If you're rich or lucky you'll live near the top of one of the city blocks, where there's still some natural light filtering in. For the middle classes it's the middle levels. And for the poor, working in the heavy industrial parts at the lower levels of the skyscrapers, it's a life of permanent murk and gloom. Then there are the gangs and those lost souls who roam the five lowest levels and the ground, where the Peacekeepers (the police) refuse to tread.
Mostly, life is controlled by three groups of power-brokers: the noble houses who have risen to become aristocrats since the Barrier went up over 200 years earlier off the back of running all the agriculture and fishing (such as it is), the corporations who make and sell most everything (including all the food which isn't farmed), and the Church of Trinity (the real ruler, irrespective of which politicians, nobles, or executives have been doing well recently).
As with all Suzerain realms, Pulse plays a big part in Gatherall. Wizardry is taught in elite universities and labs. Shamans are hired to negotiate contracts between suitable spirits and corporations, binding them into robot bodies to do deep sea work or other jobs not suited to humans. Pulse also fuels the various cyberware implants that are used all over the city for both aesthetic and professional augmentation. And then there are the stalkers... the vampires run the Church of Trinity and giving blood is a communion of sorts on Prayerday for the average citizen.
But all this is just a tiny glimpse of what's inside that bubble of energy that holds out the Wilderlands. The truth is that Gatherall isn't one city at all, but four cities that work together, each with their own take on the Trinity religion, each with their own power structure, and each with their own problems to deal with. If you want to know more... you'll just have to go there and live the life, whether it's among the muses of A'ir or the deep-sea colonies of Vater.