Fodor's Expert Review Royal FloraHolland

Five days a week from the predawn hours until mid-morning, the largest flower auction in the world takes place in the biggest commercial building in the world—it's the size of 120 soccer fields. You can watch the proceedings from the catwalk above as carts laden with flowers and plants zip about at warp speed. The buying system is what's called a "Dutch auction"—the price goes down, not up, on a large "clock" on the wall (although there are also Internet buyers these days). Buyers sit lecture-style with buzzers on their desks; the first to register a bid gets the bunch, and they work their way through more than 30 million purchases of flowers and plants daily.