bastiony

Bastions are projecting angular structures that form part of the outer defense of fortifications, especially in star forts. They extend from the main curtain wall at the corners and are designed to allow defenders to fire along the adjacent walls, providing enfilading fire and eliminating dead zones where attackers could approach unseen.

Bastions were developed in the early modern period to withstand artillery and typify the trace italienne style. A typical bastion has two faces meeting at an angle and two flanks behind them, protected by the curtain wall and a ditch with a glacis. The arrangement enables covered firing arcs and mutual support with neighboring bastions and curtain sections.

Bastions remained central in European fortification design from the 16th through the 18th centuries, influencing fortification theory and military architecture. With advances in artillery and siege techniques, many fortifications were redesigned or abandoned in the 19th century in favor of lower-profile layouts, though bastions persist in historic sites and in some modern structures as an architectural legacy.

The word comes from the French bastion, itself from Italian bastione. In Polish, the term is bastiony; in English, bastion.