Mark the start of summer by making your way over to Tagajo Castle’s Ayame-en (Iris Park) to walk in fields of three million gorgeous iris flowers in over 800 types. On Saturday and Sunday, visitors can also enjoy stage events and numerous other activities—see below for details. The festival takes place from 10 a.m. to 4 p.m.

Also be sure to take a stroll around the site where Tagajo Castle once stood. Built in 724, it served as the provincial capital from the Nara period to the Heian period. The castle, surrounded by one-kilometer long walls on all four sides, stood on a hill offering a sweeping view of Sendai Bay. Located nearby is the Tohoku History Museum, which provides a comprehensive look at the history of northern Japan.