This rotunda houses a huge painting 110m in circumference and 12m high, showing the most striking episodes of the battle, at the moment Maréchal Ney's squadrons launch their attack on the English forces, on 18 June 1815, at around 4pm. This huge fresco was orchestrated by the French painter Louis-Jules Dumoulin in 1911. It is impossible not to be struck by the dynamism of this masterly work, the craftmanship and composition of which evoke great French military painting.