KWANGYA (광야, Gwang-ya) is a word in Korean meaning "wilderness". Wilderness means the wilds, waste, jungle or desert. KWANGYA is a world where the avatars live.
In Black Mamba, "넌 광야를 떠돌고 있어" (Neon gwangyareul tteodolgo isseo) is translated as "You wander this KWANGYA". In the song it means 'You wander this unknown world'. In NCT U’s lyrics for their single, titled "90’s Love", "광야를 넘어 더욱 가까이 와" (gwangyareul neomeo deoug gakkai wa) is translated to "Come closer beyond the KWANGYA". In this song, it means to 'Come closer beyond the wilderness or world'.
In 'ep1. Black Mamba', KWANGYA is described as an unruled and infinite place located beyond FLAT. NAVIS can open portals to this location, while the æ didn't seem to have heard of KWANGYA before. The Black Mamba is disrupting SYNK from there.
In the Next Level music video, the coordinates of KWANGYA were revealed (37°32'40.2"N 127°02'40.0"E (37.544500, 127.044444)). These coordinates are the location of S.M. Entertainment's Seoul offices.