63-year-old “Grandpa Amu,” whose real name is Wang Dewen started his YouTube channel to post crafts and cooking tutorials. His videos are intentionally long, meant to be appreciated slowly so viewers gain knowledge while maintaining a peaceful mood.

In this video, Grandpa Amu is building a complex “Luban lock” for his grandson, and many have started calling Amu the modern-day “Lu Ban” – after the famous structural engineer who is said to have invented this toy.

A Luban lock is a traditional Chinese folk educational toy made from carved wood, shaped so that the concave and convex parts interlock inside the structure perfectly. They come in various shapes and sizes, with different internal structures, and are usually easy to manipulate.

Check out more on the Grandpa Amu Facebook fan page.