Bastion fort
Early modern fortification style built to withstand cannon fire
A bastion fort or trace italienne (a phrase derived from non-standard French, meaning 'Italian outline') is a fortification in a style developed during the early modern period in response to the ascendancy of gunpowder weapons such as cannon, which rendered earlier medieval approaches to fortification obsolete. It appeared in the mid-fifteenth century in Italy. Some types, especially when combined with ravelins and other outworks, resembled the related star fort of the same era.
From Wikipedia, under CC BY-SA. More on occurri.