Codex of the Synapse: Folio D1.2
The earthly site of the Synapse has never been located, nor has even a credible ruins been excavated. The now-miniscule fragments of the Synapse have long been globally dispersed, like so much dust. This dispersal, though widespread, is not homogeneous, and tiny shards of the "original" Synapse have concentrated in certain areas of the local-world known as Synaptic Loci. These Loci can occur on any scale, sometimes occupying vast geographical areas (forming the basis for periodic migration routes of the Keepers), and at other times remaining highly localized within a single building, room, or even quite ordinary objects (which then display rather extra-ordinary qualities).
Synaptic Loci, although composed of broken fragments, are nonetheless part of the Synapse, and as such become sites of frequent and potent Synapse Experiences. Many of the sacred or pilgrimage sites in our local-world, at one time or another were probably Loci. But Synaptic Loci have occurred in mundane places as well. The solitary dome which remained standing amidst the rubble of Hiroshima; the route tracing the dancing epidemics of 14th Century Europe; the bizarrely ill-fated Tacoma Narrows bridge. Where the exceptions thrive, and reality becomes a doubtful assumption, there is likely to be a Locus at work. The fractures along which things break inexplicably, the keys that vanish, or fit too many doors, the penny which flips only tails, and even the virus-infected computer disc, may often indicate the presence of a Locus, revealed in veins that often follow the calligraphy of the Pattern Language Script.
The Loci are not stable. They seem to shift in accordance with the perpetually changing Pattern Language Emissions from neighbor-lattices. A specific location may at one point have very little Synaptic content, and then centuries, years, or seconds later, become a powerful node of Synaptic activity. No reliable way to predict appearances of the Synapse has been discovered. However, a taxonomy does exist to classify a manifestation of the Synapse once it has appeared, which The Keepers refer to as the Four Domains.