The bulb fields are a seasonal attraction, in the spring end of March to the end of May. The main bulb-growing area is on the sandy soil behind the dunes, between Haarlem and Leiden. If you just want to see the flowers briefly, you can do that from the train between Haarlem and Leiden. There are also signposted cycle routes through the bulb fields, such as the Leidse Bollenroute, a 37 km route, starting at the rear of Leiden Station.
Keukenhof
Millions of tourists from all over the world visit this park and the enormous surrounding flower fields in spring.