NGII Orthophoto (정사영상) (opens in a new tab)
National Geographic Information Institute
Cost Free with registration Licence Open- Orthophoto
National open imagery Openly licensed aerial orthophotography at 1 m or finer covers about 70% or more of the land area.
NGII releases orthophotos from 2010 onwards at 12 cm in urban areas and 25 cm elsewhere, free of charge with no restriction on use, after login to the National Map portal.
Free is not the same as open. Cost is what you pay to get the data; the licence says what you may do with it. How cost and licence are defined
National Geographic Information Institute
Cost Free with registration Licence Open