Obama Onsen is an onsen, or hot spring resort, established in 713 and located in Obama, Unzen, Nagasaki Prefecture, Japan. It is known for having the hottest and most active springs in Japan, with some of them reaching 80-100 °C and producing over 15,000 tons of hot water daily. The area was formerly part of Hizen Province. Its location near the sea shore allows one to see the sun setting, which makes it a popular location to visit in the evenings. The poet Saito Mokichi wrote about Obama Onsen in his poem Sunset Plaza, and a monument with the words of the poem was erected near the onsen.Obama Onsen is famous for its Obama Chanpon a dish made of noodles, seafood, and vegetables. The onsen has about 20 stores and restaurants nearby, serving everything from Western style food to sushi, alcoholic beverages, and various interpretations of the Obama Chanpon. Shrimp are found in abundance along the beaches near the onsen, and a special soup is made from them. The onsen was designated as a National Recreation Onsen in 1962, and was first recorded in a topographic record in 713.The onsen is accessible by bus from Isahaya Station on the Nagasaki Main Line and Ōmura Lines run by JR Kyushu, as well as the Shimabara Railway Line. The ride is about 60 minutes. A fireworks show is held annually in December at the onsen.