Closterkeller is a Polish gothic rock band formed in Warsaw in 1988 by Anja Orthodox, Przemysław Guryń, Jacek Skirucha, and Tomasz “Wolfgang” Grochowalski. Despite numerous lineup changes, Orthodox has remained the group's vocalist and sole continuously active original member. Closterkeller released their debut album, Purple, in 1990, followed by Blue (1992) and Violet (1993), the latter becoming one of the band's breakthrough releases. They continued with Scarlet (1995), Cyan (1996), and Graphite (1999), developing a style combining gothic and atmospheric rock with influences from new wave, heavy metal, psychedelia, and electronic music. Subsequent albums include Nero (2003), Aurum (2009), Bordeaux (2011), and Viridian (2017). Closterkeller became one of the forerunners of gothic rock in Poland and influenced bands including Moonlight, Artrosis, and Delight. In 2025, they released the album Argento.