Endovier is a slave camp in the northern portion of Adarlan on the border with Terrasen, nested between the Ruhnn Mountain range and Oakwald Forest. The Salt Mines of Endovier, are notorious for the short life span of its workers. Enemies to Adarlan, rebels, and accused magic practitioners are sent to slave away in Endovier until their deaths.
In the shadows of the gray Ruhnn Mountains, Endovier is constantly bleak and overcast. Little more than a compound encircled by a large wall, it contains few buildings. Only a passage through the wall enclosed by iron gates allows entrance and exit to the compound. A large, shining building surrounded by a courtyard lined with lanterns houses Endovier's various Officials and Overseers. It is a standard grid of hallways and stairways, floored in marble, with iron chandeliers hanging from the ceilings. It also contains a throne room, marked by thick red-and-gold glass doors. The throne room itself contains a large, grapevine shaped chandelier and an ornate redwood throne upon a raised dais. Slaves are housed in a large, wooden building. There are also some ramshackle sheds that are used to refine the rock salt. Various mine shafts delve into the mountain for the mining of rock salt.
Thousands of slaves occupy Endovier and are escorted everywhere in shackles and at sword-point. Slaves mine rock salt in the dark shafts before dawn until after dusk, leaving the slaves in a near constant state of darkness. Whipping posts are used often to break rebellious slaves and the crack of whips are often used as a threat of violence, leaving the workers cowering in fear. Guards kill any escaping prisoner within three feet of their mine shaft. As the average life expectancy of the slaves is a month, mass graves are dug behind the refining sheds.
A few years before the series, the King of Adarlan builds Endovier and Calaculla to hold the prisoners from Eyllwe and Terrasen. After being betrayed by her fellow assassins, Celaena Sardothien is captured and sentenced to work in the Salt Mines alongside a large population of Eyllwe rebels. Stripped of her hair and clothes, she is chained and whipped with the others, although special care was taken to ensure her wounds never closed as salt was rubbed into her lashes. The Eyllwe prisoners took turns every night to clean her back along with the other wounded. Following her first whipping of twenty-one lashes, a young woman slipped Celaena a tin of salve to aid in her healing, but was subsequently raped and killed by four Overseers. After serving eight months of her sentence, Celaena snapped on the anniversary of her parents' murder and killed the four Overseers in addition to twenty others in a suicide attempt. During the Heir of Fire, a slave uprising in Calculla prompts the King of Adarlan to send legions of soldiers to violently subdue the slaves, massacring the entire populations of both Endovier and Calculla and eliminating most of the loyal populations of Terrasen and Eyllwe.