Kagawa's Kotohiki Park is one of the destinations on Japan's Top 100 Cherry Blossom viewing sites list, and it's filled to the brim with springtime beauty. Several hundred Somei Yoshino cherry trees can be found on the grounds here, and they're even illuminated after dark during the blooming season.
Typically, the best time to visit in order to catch the trees in bloom is from late March through until early/mid April. Admission to the park is free of charge.