Nikko, town (1990 pop. 20,128), Tochigi prefecture, central Honshu, Japan, in Nikko National Park. It is a tourist resort and religious center, famous for its ornate temples and shrines, dating from the Yedo period (1600-1868) and notable for rich coloring. Within the shrine of Ieyasu is the Yomeimon (Gate of Sunlight), perhaps the most beautiful gate in Japan. The park is noted for its mountain scenery, waterfalls, and cryptomeria forests. Nikko has Buddhist as well as Shinto shrines.