'U' is for 'The Uncanny Valley.' You probably saw this coming.

‘U’ is for ‘Uncanny Valley,’ something you’ve doubtless heard of by now. The Uncanny Valley is a titanic canyon dividing the continent, running from the north-edge of the ocean and splitting into three smaller valleys at the most southernly border. It is so vast that it is the only thing that has prevented The Empire of Gold and Jade from colonizing The Frontier in the west.

The Uncanny Valley sports several unique features. Its basins are notoriously warm, supporting multiple broad jungles that themselves are home to most of the world’s deluxe-class sauropods like brachisaurs and tyrannosaurs. The northern region is the exclusive home of gryphons, and the world’s only manticores live in its southern region. These large biological creatures have also attracted most of the world’s remaining automatons, holdovers from the Gremlin Age, who hunt sauropods and manticores alike. In addition to its vastness, these dangerous inhabitants make it still harder to cross. There are families of triclopes who advertise their ability to help you cross, though it is some of the most hazardous work in the world.

A unique geological feature, The Uncanny Valley is believed the result of an apocalyptic quake that split the continent, but it predates any written history. It has famed depths, creases and cracks in its basin allegedly running deep into the core of the planet, or to the origin of the World-Ocean. He first succubae were discovered slumbering deep within its crevices, along with structures like underground temples that also predate any doradic or impish culture. Optimists believe answers to the world’s apocalyptic cycle could be down there. Pessimists think succubae are the beginning of the awful things you’d be better off leaving alone down there.

Though a wonder of the world, most cultures stay away from The Uncanny Valley. Its wildlife is too dangerous to approach unless you’re deliberately rustling sauropods or farming gryphon feathers for all-chemistry. The Empire of Gold and Jade have plans to build a bridge across its gap, yet no structure of such a size has been erected for the entirety of the Human Age. Humanists consider that a good reason to build one.

UPDATE: This addition is for Larry Kollar, who in a previous post asked why the Uncanny Valley doesn't flood. After all, if it's a canyon stretching from ocean to ocean, it ought to be wetter than it is. I meant to be ambiguous about this, but not so ambiguous as to not answer it at all. The Empire of Gold and Jade has charted the southern end on the Uncanny Valley, which terminates in a half-frozen ocean, and found it mildly above sea level, and usually quite waterlogged, if not lake- or river-logged. Their attempts for expansion in the south have mostly been ocean-based with their fledgling fleet. However the northern edge has never been charted, in part due to the extremely hot climate, and in part due to the high population of gryphons. Human eyes may never have laid upon the northern opening of the Uncanny Valley - something my fiction is going to go into, and which makes a little mum about.