Next to Budolfi Kirke, the 15th-century Monastery of the Holy Ghost is one of Denmark's best-preserved monasteries and the only one that admitted both nuns and monks. The building was erected in several stages in the 15th and 16th centuries, and the duty of the first nuns and monks to live there was to look after the sick and aged. Coincidentally, the building is now a home for the elderly. During World War II, the monastery was the meeting place of the Churchill Club,
a group of Aalborg schoolboys who earned world fame for their clever sabotage of the Nazis—their schemes were implemented even after the enemy locked them up.