Saitama's Yono Park was originally opened in 1878, and it's a popular destination to enjoy spring's roses – it's home to somewhere around 200 variants of them. When the flowers are at their best an annual festival takes place on the park grounds, and it also includes fun activities like stage performances, sales of rose saplings, plus food and drink available for purchase.
For those who can't visit during the rose blooming period (May timeframe), the park is also a popular spot to enjoy cherry blossoms earlier in the year.