As many of the readers will surely have guessed, militaty architecture and even more, Renaissance militaty architecture, is among my favourite pursuits. These plans on the construction of the characteristic bastion fortifications, belong to the treatise “Rudimentos Geométricos y Militares” by the Spanish engineer Sebastián Fernández de Medrano, printed in 1677 at Brussels. Spanish and Italian engineers at the service of the Spanish crown were among the best in the world at that time.