Running from late May through until early June, Saitama's Sky of Poppies event at the Sainokuni Fureai Ranch showcases an astounding number of these lovely blooms. The venue covers a space of around 5 hectares, and there are approximately one and a half million flowers to appreciate. Because of the elevation here (it's around 500 meters above sea level), you can often get some ethereal shots with clouds covering the surrounding mountains.
Adult admission to the event is priced at 400 yen. Elementary-aged students and below receive free admission.