Question: When did the neighboring country of where Deoksancheon is located conduct its first nuclear test?

full_context: Document 1: Suseo-dong: Suseo-dong is a ward of Gangnam-gu in Seoul, South Korea. The name, "Suseo" originated from the feature of Han River running through the western part of the region. Suseo-dong is also home to the Tancheon park.
Document 2: Nuclear weapons testing: Underground tests in the United States continued until 1992 (its last nuclear test), the Soviet Union until 1990, the United Kingdom until 1991, and both China and France until 1996. In signing the Comprehensive Nuclear - Test - Ban Treaty in 1996, these states have pledged to discontinue all nuclear testing; the treaty has not yet entered into force because of failure to be ratified by eight countries. Non-signatories India and Pakistan last tested nuclear weapons in 1998. North Korea conducted nuclear tests in 2006, 2009, 2013, 2016, and 2017. The most recent confirmed nuclear test occurred in September 2017 in North Korea.
Document 3: North Korea and weapons of mass destruction: North Korea has a military nuclear weapons program and also has a significant quantity of chemical and biological weapons. As of 2003, North Korea is no longer a party to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The country has come under sanctions after conducting a number of nuclear tests, beginning in 2006.
Document 4: List of states with nuclear weapons: Country Warheads (Deployed / Total) Date of first test Test site of first test CTBT status Delivery methods Number of tests The five nuclear - weapon states under the NPT United States 1,800 / 6,800 16 July 1945 (``Trinity '') Alamogordo, New Mexico Signatory Nuclear triad 1,054 Russia 1,950 / 7,000 29 August 1949 (`` RDS - 1'') Semipalatinsk, Kazakhstan Ratifier Nuclear triad 715 United Kingdom 120 / 215 3 October 1952 (``Hurricane '') Monte Bello Islands, Australia Ratifier Sea - based 45 France 280 / 300 13 February 1960 (`` Gerboise Bleue'') Sahara, French Algeria Ratifier Sea - and air - based 210 China? / 270 16 October 1964 (``596 '') Lop Nur, Xinjiang Signatory Suspected nuclear triad. 45 Non-NPT nuclear powers India 0 / 110 -- 120 18 May 1974 (`` Smiling Buddha'') Pokhran, Rajasthan Non-signatory Nuclear triad 6 Pakistan 0 / 120 -- 130 28 May 1998 (``Chagai - I '') Ras Koh Hills, Balochistan Non-signatory Land and air - based. 6 North Korea 0 /? 9 October 2006 Kilju, North Hamgyong Non-signatory Suspected land and sea - based. 6 Undeclared nuclear powers Israel n.a. / est. 60 -- 400 1960 -- 1979 incl. suspected Vela Incident Signatory Suspected nuclear triad.
Document 5: 2006 North Korean nuclear test: The 2006 North Korean nuclear test was the detonation of a nuclear device conducted by North Korea on October 9, 2006.
Document 6: Geography of Japan: Japan is an island nation in East Asia comprising a volcanic archipelago extending along the continent's Pacific coast. It lies between 24 ° to 46 ° north latitude and from 123 ° to 146 ° east longitude. Japan is southeast of the Russian Far East, separated by the Sea of Okhotsk; slightly east of the Korean Peninsula, separated by the Sea of Japan; and east - northeast of China and Taiwan, separated by the East China Sea. The closest neighboring country to Japan is Russia.
Document 7: Duiwenhoks River: Duiwenhoks River, located in Western Cape, South Africa, drains the Langeberg Mountains and flows south to the coast, entering the sea west of Mossel Bay in the Southern Cape. The river is approximately 83 km long with a catchment area of 1 340 km. The Noukrans River is a tributary.
Document 8: Anyangcheon: The Anyangcheon is a river in Gyeonggi-do and Seoul, South Korea. It has its source on the slopes of Mount Gwanggyo in the city of Uiwang and flows north, through the city of Gunpo, where a major cleanup operation saw several species of birds return to the area in 2005. Here, though, the water table remains depleted. The river then flows through Anyang City, where it is met by its major tributary, the Hakuicheon stream. From here, it loops around to the west before continuing north to the border with Gwangmyeong City. As the river passes to the west of Mount Gwanak, it forms the border between Gwangmyeong and Seoul, where it is lined on the Gwangmyeong side with rape fields and cherry blossom trees. After the stream is joined near Guil Station from the west by the Mokgamcheon stream, which forms another border between Gwangmyeong and Seoul, it is then totally within the capital. Here, it is also joined from the east by the Dorimcheon and passes through a conservation zone for migratory birds which was established after a 2005 cleanup operation, whereafter it joins the Han. Most of the length of the river has a path alongside providing easy access, the only parts without this lying in Uiwang. Seoul City Council has embarked on a programme of exclusive cycle path creation alongside its waterways, including the Anyangcheon, to be completed in 2010.
Document 9: Geography of Vietnam: Vietnam is located on the eastern margin of the Indochinese peninsula and occupies about 331,211.6 square kilometers, of which about 25% was under cultivation in 1987. It borders the Gulf of Thailand, Gulf of Tonkin, and Pacific Sea, alongside China, Laos, and Cambodia. The S - shaped country has a north - to - south distance of 1,650 kilometers and is about 50 kilometers wide at the narrowest point. With a coastline of 3,260 kilometers, excluding islands, Vietnam claims 12 nautical miles (22.2 km; 13.8 mi) as the limit of its territorial waters, an additional 12 nautical miles (22.2 km; 13.8 mi) as a contiguous customs and security zone, and 200 nautical miles (370.4 km; 230.2 mi) as an exclusive economic zone.
Document 10: List of nuclear weapons tests of North Korea: Nuclear tests Information Country North Korea Test site Punggye - ri Nuclear Test Site, North Korea Period 2006 -- present Number of tests 6 Test type underground Max. yield ~ 140 kt (U.S. intelligence) 160 kt (Revised estimates from Japanese Government) 250 kt (38 North and revised NORSAR estimate)
Document 11: South Korea: The country, including all its islands, lies between latitudes 33 ° and 39 ° N, and longitudes 124 ° and 130 ° E. Its total area is 100,032 square kilometres (38,622.57 sq mi).
Document 12: Deoksancheon: Deoksancheon is a river of South Korea. It is a tributary of the Hongcheon River in the Han River system. The river is located in a high altitude area. There are alluvium deposits along the lower end of the stream.
Document 13: South Korea: South Korea occupies the southern portion of the Korean Peninsula, which extends some 1,100 km (680 mi) from the Asian mainland. This mountainous peninsula is flanked by the Yellow Sea to the west, and the Sea of Japan to the east. Its southern tip lies on the Korea Strait and the East China Sea.
Document 14: Dorimcheon: The Dorimcheon is a river in Seoul, South Korea. It has its source in the valley between Gwanaksan and Samseongsan in southern Seoul and flows north, past Seoul National University. From Sillim Station to Daerim Station, it is covered by Line 2 of the Seoul Subway, which is elevated above the stream for this distance, so it is still possible to walk alongside the waterway. The river empties into the Anyangcheon 250m beyond the western the end of Dorimcheon Station's platforms.
Document 15: Geography of South Korea: South Korea is located in East Asia, on the southern half of the Korean Peninsula jutting out from the far east of the Asian land mass. The only country with a land border to South Korea is North Korea, lying to the north with 238 kilometres (148 mi) of border running along the Korean Demilitarized Zone. South Korea is mostly surrounded by water and has 2,413 kilometres (1,499 mi) of coast line along three seas; to the west is the Yellow Sea (known in Korea as West Sea), to the south is the East China Sea, and to the east is the Sea of Japan (known in Korea as East Sea). Geographically, South Korea's land mass is approximately 100,032 square kilometres (38,623 sq mi). 290 square kilometres (110 sq mi) of South Korea are occupied by water. The approximate coordinates are 37 ° North, 127 ° 30 East. Notable islands include Jeju Island (Jejudo), Ulleung Island (Ulleungdo), and Liancourt Rocks (Dokdo, known in Japan as Takeshima).
ground_truth: October 9, 2006
sub_queries: Deoksancheon >> country Answer: South Korea
what are the neighboring countries of South Korea Answer: North Korea
when did North Korea conduct its first nuclear test Answer: October 9, 2006