One date is worth building a trip around

National Mill Day turns nearly a thousand Dutch mills into free, open attractions for one weekend a year.

Nationale Molendag falls on the second Saturday in May each year — 9–10 May in 2026 — when the Dutch Mill Association (De Hollandsche Molen, founded in 1923 to safeguard the country's wind and water mills) coordinates more than 950 windmills and watermills nationwide to open their doors free of charge, sails turning, often decorated for the occasion. Over 100,000 people visit mills across the country on this single weekend. If your trip dates are flexible at all, this is the one weekend where the "will it actually be milling today" uncertainty at places like Zaanse Schans disappears almost entirely.

2026 date

9–10 May

Mills participating

950+

Annual visitors

100,000+

Season by season

Outside National Mill Day, the trade-off is the usual one: weather versus crowds.

Spring (April–May) gives the most reliable mix of decent weather and manageable crowds, especially outside the May weekends around Mill Day itself. Summer (June–August) is peak coach-tour season at both sites — Kinderdijk's towpath and Zaanse Schans's riverside lane both get genuinely busy by mid-morning, and arriving at opening time matters far more than in any other season. Autumn (September–October) thins the crowds again while the direct Rotterdam–Kinderdijk WaterShuttle is still running its full daily schedule (it stops after 25 October). Winter is the quietest and starkest, with shorter opening windows at ticketed attractions and a real chance of the WaterShuttle running weekends-only rather than daily.

Time of day

Both sites reward an early start more than a seasonal one.

Coach tours from Amsterdam typically arrive at Zaanse Schans from mid-morning onward, so the first train of the day genuinely buys you a quieter village and better photos before the crowds build. Kinderdijk sees the same pattern in reverse alignment with river-cruise ship schedules that often stop there — arriving with the first WaterShuttle or waterbus run of the day is the single most effective way to walk the towpath without a crowd in every frame.