Once only indicated through a sketch by Leonardo da Vinci from around 1495, concealed passageways have been discovered ...

1364 - First recorded use of a firearm. 1380 - Hand guns are known across Europe. 1400s - The matchlock gun appears. Before the matchlock, guns were fired by holding a burning wick to a "touch ...

Leonardo often spent time at the castle during the late 1400s as a member of the court ... just ideas of innovative building: paper architecture that existed only as drawings on paper, one might ...