The Spanjaardenkasteel ("Spaniards' Castle") was a castle in the city of Ghent in present-day Belgium. The castle was commissioned in 1540 by the Holy Roman Emperor and Spanish king Charles V after he crushed a rebellion by the city that same year. The castle housed a garrison of about 2,500 men. The castle was eventually demolished in the 19th century.
References
Spanjaardenkasteel Wikipedia(Text) CC BY-SA