Gangdong District is one of the 25 gu which make up the city of Seoul, South Korea. Gangdong is literally "east of the River". It is located on the east side of the city.
Jungbu Express Motorway starts in and passes through Sangil-dong, which is located in the east end of this district. In Amsa-dong, there is a Pre-historic heritage site which is about six thousand years old. At this site, there are many kinds of pottery and houses. The pottery which has been found was made of ceramic and is circular and shaped into a point similar to corn.
Wikipedia https://en.wikipedia.org/wiki/Gangdong_District
Coordinates 37°31'48.486" N 127°7'25.822" E