bourtange-obscura

Fort Bourtange was constructed in 1593
Star forts, five-sided forts designed to give guards a panoramic view of any potential attackers, originated in Italy in the 15th century
http://www.atlasobscura.com/places/fort-bourtange
http://en.wikipedia.org/wiki/Fort_Bourtange

 

bourtange-loon

Fort-Bourtange, Atlas van Loon, 1649
http://commons.wikimedia.org/wiki/Category:Atlas_van_Loon

 

forts-hollande

autres places fortifiées aux Pays-Bas
dont Brielle, à l'Ouest de Rotterdam