We also went Kinderdijk to see the windmills, but I recommend you to stay Roel's room rather than visiting Kinderdijk.
He introduced us his windmill. It was the exclusive guide tour. It was amazing! He showed us the upper floor of the windmill so that we could see everything. He also gave us the history of the windmill. He told us that it was built on 17th century. At that time, there were Samurai and Ninja in my country:) And he told us some stories about the windmills in my country. Talking with him was fun. Lastly, he showed us how the windmill works. It was great! I was sooooooo exited.