Dalmasa is a Buddhist temple on the side of Seodalsan, just behind the Seoul National Cemetery in Donjak-gu (central Seoul, south of Han River).
The temple offers a great view of the Han River and the central part of Seoul. It is also a great place to enjoy the sunset! Since it’s not a famous tourist attraction, usually the atmosphere is very calm and relaxing.
To get there you can take a bus from Heukseuk station (line 9).
website: http://www.dalmasa.org/
google maps: https://www.google.com/maps/place/%EB%8C%80%ED%95%9C%EB%B6%88%EA%B5%90%EC%A1%B0%EA%B3%84%EC%A2%85+%EB%8B%AC%EB%A7%88%EC%82%AC/@37.4987373,126.9602565,17z/data=!3m1!4b1!4m5!3m4!1s0x0:0xe08587f1bdcd01dd!8m2!3d37.4987373!4d126.9624452