The idyllic valley nestled in the Balinok Mountains was a slice of heaven to those who knew of its existence before Strahd von Zarovich's arrival. The serenity of the place was forever shattered when Strahd led a bloody crusade against the enemies of his family that ended here with the slaughter of hundreds. Struck by the scenic beauty of his most recent conquest, Strahd made the valley his home and named it after his father, the late King Barov.
The land now called Barovia is no longer part of the world that Strahd once tried to conquer. It now exists within a demiplane formed by Strahd's consciousness and surrounded by a deadly fog. No creature can leave without Strahd's permission, and those that try become lost in the mist.
By the will of the Dark Powers, the sun never fully shines in the lands of Barovia. Even during the day, the sky is dimmed by fog or storm clouds, or the light is strangely muted.
Lay of the Land
Rolling thunderclouds cast a gray pall over the land of Barovia. A deathly stillness hangs over the dark woods, which are patrolled constantly by Strahd's wolves and other servitors.
The evergreen trees of the Svalich Woods climb the sides of the mountains that enclose the valley the largest of these peaks is Mount Baratok, with its snow-covered cap and rugged slopes. Baratok's slightly smaller twin, Mount Ghakis, is mostly bald with tufts of trees here and there.
Between these two mountains stands Lake Zarovich, which is fed by streams of ice-cold water pouring down the face of Mount Baratok. On the south side of the lake rests the town of Vallaki, enclosed by a palisade. West of the two mountains, atop a hill, stands the Abbey of Saint Markovia, around which the Barovians built a walled village Krezk.
East of the mountains lies the village of Barovia, shrouded in mist and bereft of walls and defenses. The dark silhouette of Castle Ravenloft looks down on this village from its perch atop a 1,000-foot-high column of rock known as the Pillarstone of Ravenloft.
Barovians
After his armies occupied the valley and slew its inhabitants, Strahd repopulated the area with subjects drawn from his other conquered lands. As a result, Barovians have a wide variety of ethnic backgrounds and blended ancestries.
Barovians are deeply invested in their homes and their traditions. They are wary of strange peoples and customs. The way Barovians deal with strangers can be unsettling to those newcomers. Barovians have a tendency to stare openly, in silence, thereby expressing their disapproval of anything that isn't familiar to them. Barovians aren't talkative with strangers, to the extent of being pointedly rude. Most Barovians have violent tempers that boil up through their customary silence when they are provoked. They also have a social cohesiveness (thrust upon them by their weird circumstances) that can make them act together against outsiders if a Barovian is mistreated.
Barovians were a happy people once, but their history and current conditions aren't pleasant. If one manages to win the trust of a Barovian, one has a friend for life and a stalwart ally.
Barovian children aren't happy children. They are raised in a culture of fear and told time and again not to wander too far from their homes or enter the woods. They experience little hope or joy, and they are taught to fear the devil Strahd above all.
Barovian adults eke out modest livings. With no new wealth pouring into the valley, they trade in old coins that bear the profile of their dark lord Strahd. They hide their precious baubles in their houses and dress plainly outdoors, so as not to attract the attention of Strahd or his spies.
Barovians live within a closed ecosystem. Every Barovian adult is expected to learn a trade or serve a function. Barovians stitch their own clothing, craft their own furniture, grow their own food, and make their own wine. With fewer than three thousand people living in the entire valley, finding the perfect mate isn't easy, so Barovians have learned to settle for what they can get.
Vistani
The Vistani (singular Vistana) are wanderers, traveling about horse-drawn, barrel-topped wagons, which they build themselves. Compared to Barovians, they are flamboyant, dressing in bright clothes and laughing often.
Vistani are silversmiths, coppersmiths, haberdashers, cooks, weavers, musicians, entertainers, stortellers, toolmakers, horse traders, and many more, though they mostly earn money by telling fortunes and selling information. They spend whatever they earn to support a lavish lifestyle, display their wealth openly as a sign of prosperity, and share their good fortune with family and friends.
Each family or clan of Vistani is its own little gerontocracy, with the oldest member ruling the roost. This elder carries the bulk of the responsibility for enforcing traditions, settling disputes, setting the course for the group's travels, and preserving the Vistani way of life. Vistani elders make all the important decisions, but whether by choice or because of their age, tend to speak in cryptic, flowing riddles.
Vistani families and clans are closely knit. They resolve disagreements through contests that end with reconciliatory singing, dancing, and storytelling. The Vistani are quick to act when their lives or traditions are threatened and are merciless when they believe they must be. Vistani who knowlingly bring harm or misfortune to others of their kind are banished - the worst punishment a Vistana can imagine, even worse than death.
Strahd allows the Vistani to come and go as they please because he admires their lust for life and their willingness to serve him when he needs them. He also owes an ancient debt to the Vistani people. As a soldier millenia ago, he suffered a grievous injury in battle, and the Vistani tended his wounds and returned him safely to his family without making any demand for payment.