The Lost Land of Haven is not a typical geographical location in the Grand Duchy of Karameikos but a profound anomaly of myth and planar instability. The realm exists in a state of perpetual duality, for part of the time it is a corporeal land, and for the rest, it slips into the ethereal domain of Faerie, also known as the Spirit Plane or the Otherworld. This phenomenon is a result of a "mysterious and convoluted series of astrological calculations" known only to a few wise sages and the Vyalia Elves. This inherent duality frames every aspect of Haven, from its history to its people. The land's connection to the Spirit Plane began long ago after the Great Rain of Fire, and it was once a stepping stone for dark beings from the Dimension of Nightmares. Due to its temporal and physical unreliability, Haven has become a myth to most of Mystara's inhabitants.
The appearance of Haven is as dualistic as its nature. When it is on the Prime Plane, it is a land of pastoral beauty, with rolling hills and meadows, and small stands of forests to the east. The Silver Crown Mountains lie at its heart, home to the central village and the infamous Palace of the Silver Princess. When Haven shifts to the land of Faerie, the area it once occupied on Mystara becomes an empty, desolate region of forest and hills perpetually bathed in mists and fogs. The borders of this misty realm are particularly hazardous, as stepping into them can transport a traveler to a random, far-flung region of Faerie.
The culture of Haven is defined by harmony and a unique social structure. It is a land where humans, elves, dwarves, and halflings live together peacefully under the aegis of the Faeries. The population consists of a harmonious mix of races, and they are referred to as "goodly folk." This racial and social unity stands in stark contrast to the strife and cultural tension found in the rest of Karameikos. The laws and customs are governed by the Faeries and are influenced by the community's need for defense against barbaric tribes.
The Lost Land of Haven is located in the easternmost corner of the Grand Duchy of Karameikos. It encompasses an area of approximately 1,344 square miles. Its borders are delineated by the Lake of Lost Dreams to the south, the River of Lost Dreams to the east, the Altan Tepes mountains to the north, and the Dymrak Ridge to the west. The central part of the territory is defined by the Silver Crown Mountains, which contain Haven Village and the ruined Palace of the Silver Princess.
The economy of Haven is a self-sufficient model based on the combined efforts of its diverse population. The land's primary industries are farming, cattle herding, and mining. This reliance on local resources for sustenance is necessary, given the land's planar instability and its temporal disconnect from the rest of Mystara. The inhabitants were historically invited to live in Haven to aid in its defense and help rebuild the land, suggesting a cooperative and resource-sharing economic framework.
The defense of the Lost Land of Haven is both conventional and supernatural. Its initial inhabitants were peace-loving demihumans and humans invited to aid in the land's defense from attacks by barbaric tribes. The military strength is supplemented by the Faeries, who act as its aegis. The Palace of the Silver Princess, a central landmark, is now a ruin, and the surrounding area is home to monstrous creatures from a different plane, suggesting that Haven has a history of fighting incursions from chaotic forces.
The most notable relationship of Haven is its existence in a state of conjunction with the land of Faerie. Internally, the different races of humans, elves, dwarves, and halflings live in harmony, and the realm has a known, though secretive, relationship with the Vyalia Elves. On the other hand, it is in open hostility with various "barbaric tribes" that surround its territory. The temporal distortion and the random planar shifts of the land make it impossible to have any stable long-term political or economic relations with the nations of Mystara, positioning it as a mythic and lost land to the outside world.
The reputation of Haven is that of a mythic, lost land, known only to a select few. When the land is in Faerie, the area it occupies on Mystara is a place of mists and fogs, with strange voices heard within, adding to its mysterious reputation. The existence of the Palace of the Silver Princess, with its tragic history and cursed artifacts, gives the location a dark and dangerous reputation. The land is seen as a place of myth and legend, a profound enigma that exists on the fringes of the known world.