The Iya Valley (祖谷 Iya) region in Tokushima Prefecture, Japan is a scenic area known for its dramatic mountain valleys, thatched roof farmhouses and historic vine bridges. Although access has improved in recent years, the Iya Valley and the inner parts of Shikoku have historically been remote and difficult to enter, making them a favorite retreat for refugees and defeated warriors. Most notably, members of the Taira clan (aka Heike clan) were rumored to have entered the area after losing the Genpei War to the Minamoto clan in the late 12th century.
In modern times, the Iya Valley has become an increasingly popular tourist destination due to its natural environment and to being one of the last few vestiges of old world Japan. Although the west part of the valley (known as Nishi-Iya) has good road access and other tourist facilities, the eastern area known as Higashi-Iya (東祖谷) or Oku-Iya (奥祖谷) is still relatively difficult to access. Several vine bridges, once the only method for crossing the rivers, continue to span the valleys and have become a tourist attraction.