Model of two warships side by side with a siege tower placed on top of them. Inside this tower is a ballista for hurling large boulders as well as a further two, smaller stone-throwing catapults. This model shows a reconstruction based on information provided by Diodorus Siculus, Arrian and Vitruvius. These siege engines were invincible for many years, until archimedes, renowned Greek engineer, built the fearsome cranes used in the defence of Syracuse, which could seize Roman siege engines and smash them against the rocks.