Good suggestion, I think they are the largest flower auction in the world. A helpful tip: if you plan to visit, aim to arrive before 7 AM, the auction process typically concludes by 11 AM (9 AM on Thursdays), and by then, the average 20 million flowers are already en route to their buyers. Closed on weekends. Ticket info: Royal FloraHolland

You can observe everything from a walkway that spans the complex, with information available via panels or an app. The building once housed eight auction rooms accommodating up to two hundred buyers each. These rooms sit empty now, as the auctioneer operates from an office and the buyers must place their bids online. I believe the 'Dutch auction' originated at these flower auctions, where they start with a high price and the clock runs down until someone accepts the current one. This way, every two seconds per auction room, a transaction can be completed.