Himinborg is a town ruled in absentia by Heimdall, the god of watchfulness and warning. Heimdall spends all his time gazing out over Bifrost, so he is a ruler in name only, but the town still exudes an atmopshere of caution and distrust, especially of the strange or exotic. Its watchtowers are manned, even in the worst weather, by the ever-watchful priests of Heimdall.
The town is also the trading hub for much of the Norse pantheon, as it is the town that links their realm of Asgard to the mortal world. This means that there are a lot of travelers from the Prime Material plane here, and plenty of rogues and cutthroats that take advantage of the easy marks.
The town serves as something of an unofficial planar headquarters of the Fated (Rowan's Hall being their official headquarters), with many loyal to that faction's teachings present in the town.
Those who render service to the city (for instance, in battle) are given boons freely, but the town has little patience for those who haven't proven their worth, and no pity for those who cannot haul their own weight.
The bards of Himinborg are masters of promoting one's reputation, and though the long, elaborate tales may bore a smart listener, most of the folks eat up these "true enough" tales, and this kind of promotion is the only way one earns respect in Himinborg. Of course, the farther from the truth these tales are, the harder it'll be to explain to the einheriar why you can't help out when the next giant raid comes.
Himinborg supports a community of fine horn-crafting, for both drinking from and blowing into (such as a hunting horn). They draw inspiration from Heimdall's own Gjallarhorn, the legendary horn that will sound to warn the gods of Ragnarok. The horns are crafted from bulls, rams, and oxen, and decorated with images of Heimdall and Odin. The finest crafter in town is Sven Makkirsen (male bariaur, level 4 Fighter, Chaotic Good), a bariaur indep who used to be an adventurer until he took an arrow to his knee.
Nominally, the town is ruled by Heimdall, but functionally, it is ruled by a priest of his, Bjorn Hammarskold (male human, level 13 priest, Chaotic Good), a true believer in the tenets of the Fated. He speaks for Heimdall, and does little to shelter the weak and vulnerable in his community. Still, as the judge of all disputes and crimes in the community, he errs on the side of mercy, typically ruling that the perpetrator simply needs to spend some time in the town militia.
The town's walls are defended by some of the most reliable troops on Ysgard, honed against frequent raids by giants and other Nordic monsters. The actual bodies on the walls are einheriar, petitioners, volunteer warriors, and criminals for whom this is a punishment. If the threat is particularly dire, the captain of the militia is even empowered to summon valkyries from Asgard, though this is rare, as it is a point of pride that the militia here can repel nearly any threat it needs to. The person invested with authority over the militia is Heinrik Ivarsen (male human, level 17 Fighter, Chaotic Neutral), a big, strong Taker with a big, loud voice, and very little patience.
A clan of dwarves known as the Doksmids has a camp by the western entrance. They craft great metalwork, but charge exhorbitant prices, and they spend that gold almost entirely on huge amounts of ale. They are a constant source of strife to the townsfolk, who regard them as untrustworthy outsiders, but find their metalwork too fine to pass up. Their leader, Thorin the Strong, is perhaps the most hard-nosed (and red-nosed) of the bunch.
According to the bards, Arnuf Trollborn is a powerfully strong rogue who wrestled with a conugon in the streets of Sigil and won seven years' service from it. As a way of humiliating the creature, Arnulf has put it on display near the center of town, and all are encouraged to come by and mock it for its foolishness.