Every second weekend in May:Meet the wind and water mills in your area! The first National Milldag was in 1973, and in 1976 this day was combined with TheLandelijke Bicycle Day! So could and could, anyone,on the bike, visit the mills on this day! In the meantime, TheLandelijke Bicycle Day no longer exists, now thewhole month of Maydeclared Cycling Month. Also nice to know, is that there is alsoGroundare open to visitors, and it is2 daysbecome. So...