The Jeong-dong Observatory is a hidden spot that most tourists don’t know about. You can head up to the 13th floor of the Annex Building of Seoul City Hall in Seosomun. It gives you a great view of the area including that beautiful Deoksugung Palace. You can have a snack and beverage in the observatory and buy souvenirs as well. It is open 09:00 to 18:00 How to get there: City Hall Station (Seoul Subway Line 1 or 2) Exit 1.