Nurmengard Castle

Grindelwald was imprisoned in the top-most cell in the highest tower inside Nurmengard after his defeat by Dumbledore. His followers were called The Alliance. The alliance was an association of seditious witches and wizards who followed the Dark wizard Gellert Grindelwald in the early 20th century. Fanatics dedicated to Grindelwald's ideology of wizarding supremacy referred to themselves as his "acolytes".

Nurmengard Castle was located somewhere in the Austrian Alps, and functioned as a wizarding prison. Originally built by Gellert Grindelwald to hold his opponents, it also served as the base of operations for Grindelwald and his followers. Ultimately, it was used to imprison Grindelwald himself after his defeat by Albus Dumbledore in 1945, until his death in 1998.

Nurmengard was a stone fortress at the edge of a mountain. It had a tower with a cone-shaped top, possibly being a watch-tower. There was a building connected to the tower, that was slim with windows. Nurmengard also had a courtyard, which was gated. Whenever there was an outsider, one or more of Grindelwald's acolytes would interrogate them, while wanded. On either side of the courtyard were prisons with black-coloured bars, very probably enchanted by Grindelwald to hold less powerful enemies, while the other ones were held captive further inside, in the castle's interior. On top of these prisons were houses. On the mountainside, at the back of Nurmengard Castle, were a series of steps that led to a hill, where Aurelius Dumbledore would wait for his phoenix to arrive.

This tower was a square shaped tower with a cone shaped top. Inside the main building, there was a hallway with velvet carpet detailed with white lines and also a table. When Grindelwald revived the dead Qilin he had recently killed, Grindelwald went to a room with two pools of water, and placed it in one of the pools of water somewhere in the castle. This pool was possibly on the lowest floor of the castle, possibly even underground, as there were only upward-leading stairs there. Written on the walls of the room where these pools was located were rune symbols, including a fancy-looking number 3. There were also several candelabras in the room, some of which were on the ground, while some were chained to the ceiling.

Aurelius Dumbledore washed his hands in this room while talking to Queenie Goldstein. There was also a mirror that Aurelius used to send messages to Aberforth's mirror in Hog's Head Inn. Aurelius's use of the mirror was unknown to Grindelwald and the rest of the Alliance. Connected to the hallway was a room with large wooden doors. Inside the room held tables, chairs, a desk, cabinets with books, a gold chandelier, a stove and more things. The walls were coloured red and yellow with a pattern. They also had six different heraldic symbols on the walls. At the end of the room was a big window, with a staircase going down into a lower part with a table, chair and a table. Up the staircase, was a narrow staircase, leading into the tower. Half a decade later, Nurmengard turned into a gigantic, towering building made of black rock and with high walls, that is described as "jet-black", "forbidding", and a "grim fortress". The cell that was inhabited by Gellert Grindelwald since 1945 had been a dark and ominous room in the highest tower, with a hard bed and a ragged, thin blanket.

The prison was built on the orders of the Dark wizard Gellert Grindelwald in order to hold his opponents. Grindelwald's slogan "For the Greater Good" was carved over the prison's entrance.

By 1926, the castle also served as the headquarters for Grindelwald and his Alliance during the Global Wizarding War. Later in 1927, Gellert gave Aurelius Dumbledore a spare wand and bestowed him alleged information about who he might be and what Albus Dumbledore is up to.

In 1932, Aurelius and the other acolytes brought to Nurmengard a Qil