Akkadō

{{for|the asteroid|5679 Akkado}}

{{Infobox cave

| name = Akkadō

| other_name =安家洞

| photo = Akkado SHINDEN.jpg

| photo_width = 270px

| photo_caption = Inside the Akkadō

| map = Japan Iwate Prefecture

| relief=yes

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| location = Iwaizumi, Iwate Prefecture, Japan

| coords = {{coord|39|59|1.1|N|141|44|10.05|E|region:JP|display=title}}

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| depth = 280 meters

| length = 23,702 meters

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| discovery =

| geology = limestone

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| access = public

| show_cave =

| show_cave_length = 700 meters

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| website ={{official|http://www.town.iwaizumi.iwate.jp/kankoumap/akkadou.html}}

}}

{{Nihongo|Akkadō|安家洞}}, located in Iwaizumi, Iwate Prefecture, in the Tōhoku region of northern Japan, is the longest limestone cavern in Japan, with a measured length of {{convert|23702|m|ft}}.[http://www.j-cave.jp/akka/] {{Webarchive|url=https://web.archive.org/web/20120709072011/http://www.j-cave.jp/akka/|date=2012-07-09}} Journey to the Center of the Earth The cave system was designated as a natural monument by the Japanese government in 1980. Since 1991, a portion of the caverns have been open to the public for part of the year.