A siege tower or breaching tower is a specialized siege engine, constructed to protect assailants and ladders while approaching the defensive walls of a fortification. The tower was often rectangular
Assyrian attack on a town with archers and a wheeled battering ram; Neo-Assyrian relief, North-West Palace of Nimrud (room B, panel 18); 865–860 BC
The remains of the Roman siege-ramp at Masada
Medieval English siege tower
A vehicle used by GIGN featuring a mechanical assault ladder mounted on its roof, essentially a modern version of a siege tower
The ballista, plural ballistae or ballistas, sometimes called bolt thrower, was an ancient projectile weapon that launched either bolts or stones at a distant target.
Reconstructed small Roman ballista
One talent ballista (26 kg [57 lb] weight projectile) was typical for Roman era ballista. The heaviest version ever made was built by Archimedes, and used stones up to three talents (78 kg [172 lb]).
Roman 'catapult-nest' on Trajan's Column