What follows are, quite simply, locations that have become important in UnderWorld games I have run.
Ravenglass is a port on the Brooklyn Sound, hidden inside rolling fogbanks that seem to carry it along. There are no roads to Ravenglass; the only access is by water, through the mists of the Sound. Some who ply the Sound know the knack of Ravenglass, and can always plot their way; others might just find themselves in the water, lost in the mists, and the next thing they know, they're floating into the harbor. A high number of Ravenglass immigrants are Lost sailors and shipwreck survivors blown through the fog.
Ravenglass itself is thought to be a Lost place, wedged in the Radiance like a piece of food too big to be swallowed. Time behaves strangely there, ebbing and flowing like the tide. No sun shines in Ravenglass anymore - instead the sky is constantly starry, filled with dark clouds, and the moon always hangs in the air, cycling through its paces without moving through the sky.
Upon entering the harbor of Ravenglass, one immediately notices the surroundings - the city is built on the beach at the juncture of two cliffs which shelter the harbor. Atop one of the bluffs is a lighthouse, whose fire always burns; the other, which faces the mouth of the harbor, holds a keep armed with Artificer-built defense weapons. Due to the lack of sun, the entire place is constantly lit with torches and gas lamps (fed by an apparently endless local supply - no citizen has ever had to pay for heat). It occasionally rains, and in the winter it snows.
Inside the city, there are vast gulfs in architecture from one building to the next. The oldest structures are built in the Roman style - there is even a working bathhouse, which runs 24 hours a day. Most are relatively newer, stone and woodwork and clay. Scattered among these real buildings, and stretching along the caved cliff faces that surround the port, are structures scavenged from broken ships and the ruins of less fortunate Roman erections, all hobbled together haphazardly.
Finally, behind and above the city, there is a castle carved into the rock itself, polished until it shines. Flanked by two guard towers, each guarding one of the passes into whatever lays beyond the cliffs, the castle is the home to King Derek of Ravenglass, the Lord of this Domain. He has claimed the wildernesses beyond the mountain as his personal hunting ground, and violating its borders is one of the few ways to get killed or permanently banished.
Despite its apparent isolation, Ravenglass is rarely without visitors, many coming from places far distant from the Navigators who ply the Brooklyn Sound. Merchants of all stripes are found plying their wares, making it one of the richest and most diverse bazaars around. Most of the income of the city comes from fees charged to the merchants (by the hour) for plots in the market.
Derek is irrevocably linked to Ravenglass - as long as the land lives, so will he, and as long as he is hale, so is the land. He is a rather nondescript human with an obvious air of royalty, but also sadness; his people know that he is unable to ever leave this place. Derek prefers peace and security in his Domain, and recognizes no Guild's sovereignty. He asks all that arrive to follow one law: to perform no deadly violence. Only his guard are exempt.
Those who fail to follow this rule face banishment from Ravenglass - no longer will the fogs open to let them in. Derek presides over all cases, and is the final judge on banishment, or any other punishment for lesser infractions. The law specifically does not include brawls, nor will Derek punish someone from defending themselves.
Leaving Ravenglass is as easy as entering, though without knowing the knack, it is difficult to choose where the mists will go. More than a few have stumbled down the wrong path, never to return home.
Ravenglass is a good bridge between UnderWorlds. Especially the Triangle.