Mount Unzen is a very active volcanic complex located on the island of Kyushu near Nagasaki in Japan. The area is of great interest to vulcanologists. It is ranked as a Decade Volcano, one of 17 worldwide that warrants special scrutiny because of its activity, devastating eruptions and proximity to large populations. In addition, the Unzen hot springs and natural beauty draw tourists to the area's local resorts.
Unzen is part of the Japanese National Parks system. It is composed of several different overlapping volcanoes, the tallest of which, Heisei-shinzan, is just under 5,000 feet high. The area makes up the largest part of Shimabara Peninsula. Because of several devastating eruptions in the past, including one as recent as 1991 that killed 43 people, humans do not live there. This has allowed the area's natural beauty to flourish and encouraged the growth of several resorts and sanatoriums in the region, according to the Unzen Tourist Association.
The Unzen hot springs are known for their high acidity and sulphur content. Many Japanese tourists who visit the area do so because the springs are reputed to be beneficial for skin conditions, like eczema. Some of the 30 or so springs reach over 190 degrees Fahrenheit, making it especially important that visitors pay attention to signs and guides before entering them.