Nurmengard

Nurmengard is a fictional prison fortress featured in J.K. Rowling's Harry Potter series. It is located in a remote mountain range, implied to be in Eastern Europe. The castle was built by the dark wizard Gellert Grindelwald in the early 20th century. Grindelwald used Nurmengard as his base of operations and a place to imprison his enemies, as well as those who opposed his vision of wizarding supremacy.

The fortress is described as a formidable and grim structure, surrounded by harsh terrain and a chilling atmosphere. It is heavily protected by dark magic. Within its walls, prisoners were subjected to severe conditions, though the exact nature of their suffering is not detailed in the books. Nurmengard is notorious for its role in Grindelwald's rise to power and his subsequent reign of terror.

Later in the series, Albus Dumbledore defeats Grindelwald in a legendary duel, after which Grindelwald himself is imprisoned within Nurmengard. He is said to have occupied a cell in the highest tower of his own fortress, living out his remaining years in isolation. The prison itself continues to stand as a symbol of Grindelwald's cruelty and the dark period of wizarding history he represented. The name "Nurmengard" suggests a place of suffering or torment.