Jongmyo is a shrine dedicated to worship kings and queens of the Joseon Dynasty. It is a UNESCO World Heritage site and is located in central Seoul, close to several palaces. When making a trip in this general area, you will definitely not run out of stuff to see.
I was lucky enough to be able to visit it on May 1st, which marks the Royal Ancestry Ritual. On this day, an ancestral Confucian ritual is reenacted. This is accompanied by music and dance performances.
There are two different shrine sites, both of which have their own ceremony featuring traditional music and a performance. It is an interesting sight to see, although I can’t see myself sticking around and watching this for a full hour (or even longer).
However, the real highlight was the arrival of the King to the shrine. Of course, he is accompanied by a large entourage who march up to the Shrine, which is a pretty spectacular sight.
After that, the king enters (or rather, is carried into) the facilities to do his thing.
If you happen to be in Seoul on May 1st, this ceremony is definitely well worth your time.