From 1838 to 1851, Thon was employed in construction of the Neo-Russian Grand Kremlin Palace and the Kremlin Armoury in Moscow. The grandiose palace, famed for opulent interiors of its 700 rooms and halls, was meant to symbolize the grandeur of the Russian state. It was a daring design which incorporated parts of earlier structures that had been standing on the spot. The palace has served successively as an official residence for the Russian tsars, Soviet rulers, and the Presidents of the Russian Federation. At the same time, Thon rehabilitated the abandoned Izmaylovo Estate into an almshouse for the veterans of the Napoleonic Wars.