The city emblem features the design of "Nagai, the city of water, greenery, and flowers." The garden covers an area of 3.3 hectares, where hundreds of varieties of irises bloom vibrantly. Nagai Iris Garden is not only known for the abundance of its stocks and varieties, but also for preserving the unique varieties called the "Nagai Old Varieties." During the festival period, there are also free park tours by sightseeing volunteer guides, the sale of iris seedlings, and various other events. A structure called "Umbrella Sky" is set up at the north entrance of the park and is popular as a photogenic spot. *The festival period may change according to the blooming status of the irises.