유유플러스(주)

It was good.

There were so many things to do and it was fun

Very nice

Here is the info for Gyeongbokgung tickets. You can buy them at the kiosks (card only) or at the ticket office. There are multiple guard changing ceremonies throughout the day, and you don't need a ticket to watch them, but it gets very crowded, so I recommend going early. It's free if you wear a Hanbok.