The palace, directly across the street from the Seoul City Hall and easily accessible using Exit 2 from the metro City Hall stop, is worth a 2 to 3 hour visit -- especially if one is a senior (65+) for which it is free of charge. The well preserved buildings interesting, as is the art museum which focuses on Korean painters -- a genre which is unfamiliar to many westerners (also free for seniors). Planning your visit around the changing of the guard ceremonies is prudent, as well.

A high school student called Esther who is my volunteer guide made the trip perfect. She was able to explain about the different buildings, meaning of motifs and emblems, and story of the Princess. Weather is very good in June with sun and nice temperature. Just in time to catch the change of guards after my tour. Best experience, thank you!

We didn’t go inside the palace but watched the lavish and dramatic changing of the guards at 3:30 (I think the other times are 12 and 2pm but check that if going).
We get lucky enough to try on free Hanbok costumes to experience the change of the guards and pose with the guards after their ceremony. The whole thing lasted about 20 minutes and there were explanations in English. The outfits were colourful. There’s a huge drum that’s beaten too.