National Geographic : 1938 Feb
CASTLES AND PROGRESS IN PORTUGAL A FEW CENTS BUYS THE WOMEN'S POTTERY; THE BUILDING COST PORTUGAL $20,000,000 King Joao V imperiled his country's finances to build the immense convent at Mafra, north of Lisbon, in fulfillment of a vow that if he were blessed with an heir to the throne he would convert his poorest monastery into the richest (page 148). Some 45,000 workmen were employed at one time. There are more than 4,500 doors and windows. Completed in 1735, the building is now a barracks and military school.