A network of secret tunnels drawn by Leonardo da Vinci in 1495 has now been discovered beneath an Italian castle.

Are colored European coins a creative enhancement or an unwelcome alteration? While some collectors embrace the vivid designs ...

The math that describes the branching pattern of trees in nature also holds for trees depicted in art—and may even underlie ...

The need for secret communications arose very early in civilization. It progressed due to the “intellectual arms race” ...