Ōnuma Quasi-National Park

{{Short description|Quasi-National park in Hokkaidō}}

{{Infobox Protected area

| name = Ōnuma Quasi-National Park

| alt_name = 大沼国定公園

| iucn_category = II

| photo = komagatake_dusk.jpg

| photo_caption = Hokkaidō Komagatake, in the center of the park, at dusk.

| map = Japan

| map_alt =

| map_caption =

| map_width =

| location = Hokkaidō, Japan

| nearest_city = Nanae

| coordinates = {{coords|42.0121|140.671|region:JP-01|notes=[http://protectedplanet.net/sites/Onuma_Quasi_National_Park Onuma Quasi National Park] protectedplanet.net|display=inline, title}}

| area = {{Convert|90.83|km2|mi2|abbr=on}}

| established = July 1, 1958

| visitation_num =

| visitation_year =

| governing_body =

| url =

|embedded = {{Designation list

| embed = yes

| designation1 = Ramsar

| designation1_offname = Onuma

| designation1_date = 3 July 2012

| designation1_number = 2058{{Cite web|title=Onuma|website=Ramsar Sites Information Service|url=https://rsis.ramsar.org/ris/2058|accessdate=25 April 2018}}}}

}}

{{nihongo|Ōnuma Quasi-National Park|大沼国定公園|Ōnuma Kokutei Kōen}} is a {{Convert|90.83|km2|mi2|abbr=on}} quasi-national park on the Oshima Peninsula in southwest Hokkaidō, Japan. The park encompasses the volcanic {{nihongo|Hokkaidō Komagatake|北海道駒ケ岳|Hokkaidō Koma-ga-take}} as well as the {{nihongo|Ōnuma|大沼}} and {{nihongo|Konuma|小沼}} ponds, which abut against the west slope of the mountain. The park, which was designated as quasi-national in 1958, is the smallest major park in Hokkaidō.

Ōnuma and Konuma were created when mudflows due to eruptions of Hokkaidō Koma-ga-take dammed up depressions at the base of the mountain. The ponds, which are dotted with watershields, are surrounded by birch and maple forests.