Nikkou is a city located in the mountains of Tochigi Prefecture, Japan. Located approximately 140 km north of Tokyo and approximately 35 km west of Utsunomiya, the capital of Tochigi, it is a popular destination for Japanese and international tourists, housing the mausoleum of shogun Tokugawa Ieyasu (Nikkou Toushou-guu) and that of his grandson Iemitsu (Iemitsu-byou Taiyuu-in), as well as the Futarasan Shrine, which dates to the year 767. There are also many famous hot springs (onsen) in the area. Elevations range from 200 to 2,000 m. The mountains west of the main city are part of Nikkou National Park and contain some of the country's most spectacular waterfalls and scenic trails. As of January 1, 2008, the city has an estimated population of 92,181.
Shoudou Shounin (勝道上人) established the temple of Rinnou-ji in 766, followed by the temple of Chuuzen-ji in 784. The village of Nikkou developed around these temples. The shrine of Nikkou Toushou-guu was completed in 1617 and became a major draw of visitors to the area during the Edo period. A number of new roads were built during this time to provide easier access to Nikkou from surrounding regions. Nikkou Toushou-guu, Futarasan Shrine, and Rinnou-ji now form the UNESCO World Heritage Site Shrines and Temples of Nikkou.
During the Meiji period Nikkou developed as a mountain resort, and became particularly popular among foreign visitors to Japan. The Japanese National Railways began service to Nikkou in 1890 with the Nikkou Line, followed by Tobu Railway in 1929 with its Nikkou Line.
Nikkou was incorporated as a town in 1889, part of Kamitsuga District. It was upgraded to city status in 1954 after merging with the neighboring village of Okorogawa. On March 20, 2006, the city of Nikkou merged with the city of Imaichi and the municipalities of Ashio, Fujihara, and Kuriyama to create what is officially the new city of Nikkou. The new city hall is located at the former Imaichi City Hall: the former Nikkou City Hall is now known as Nikkou City Hall - Nikkou Satellite Office.