Author 'Boucher Marc dit de Meilh' (Id 131974 ) : Medieval castle can Demptézieu (Isère). Photograph of a narrow horizontal opening angle tower of the castle. Opening special and rare that appears in the 'heavy' fortifications in the early twelfth century, however, multiplying the XIII century to defend against all attacks. This opening allowed the archers to launch their projectiles (dashed arrows and a crossbow.) It was also used to watch without being seen ... Only toward the end of the fourteenth century that this type of opening is becoming increasingly rare and is replaced by large window to window as can be seen on the turret or tower exposed in this series on medieval fortress Demptézieu Isere. Marc Boucher said Meilhan.