Here is the leading banner. It says Bucheonim Ohshinnal. Bucheonim is Buddha in Korean, and OhshinNal is literally the day he came, so in other words, Buddha's Birthday. This was followed by the taxis of Seoul, decked out with lanterns.
Then came a very royal procession, something similar to what you might see at a palace around Seoul, but maybe a little bigger.
I think nearly every temple in the area was represented here. You could see every temple carrying a banner with their name, then they generally had some group of music or dance performers, and maybe or maybe not a giant lantern (which may or may not have had animatronics or flame throwers) and then a big bunch of the temple's worshipers in the rear, carrying some kind of intersting shaped lanterns. My favorites of the evening were the umbrella shaped lanterns. Stupid camera...
Here's an example of one of the flame throwing dragon lanterns. I kept waiting for it to catch itself on fire. I don't know if you can see the fire coming out of it's mouth here.
Anyway, the parade was much longer than I expected. A bit more than two hours of watching lanterns pass by was a long time for my bum sitting on a very tall subway vent. But, we stayed til the bitter end. Anyway, it was a good time. Make sure you make it down next year!