Best way to get to Seoraksan National Park

I am travelling on Chuseok, ideally would like to leave at 6:00 on Monday to Seoraksan National Park and was wondering the best way to do this. I am afraid that I will not get a seat on a bus, is there a train?

I am currently living in Dongtan, 30 minutes outside Seoul and close to Suwon...

Any other suggestions for Chuseok??? Thanks!

When travelling at peak times, I either go to the bus station in advance and buy a ticket, or ask a Korean to book a ticket online for me.

Go to Suwon Bus Terminal, catch a direct bus to Sokcho at 08:00, 09:50, 11:10, 12:30, 14:00, 15:30, 17:30, 18:30. Est. journey time is 3 hours 40 minutes, single fare for adult is KRW 23300.

Train isn't really an option for Suwon-Sokcho.

I did it 4 years ago during Chuseok but I bought my ticket ahead of time. I took the midnight bus from the Express Bus terminal and arrived to watch sunrise on the beach. Best option is to go to Seokcho as mentioned above.

6 pm on Monday will be peak Chuseok travel time...you probably do want to buy a tick in advance. I agree with Jake that you should take a bus to Sokcho and from there catch a local bus into Seorak-dong, the minbak (inn) ghetto just outside the park gate. You might want to try a more off-peak time like midnight or at least 9 or 10 p.m....I can recommend any of the other (less "famous") national parks...Byeonsan-bando on the southwest coast is pretty nice and not too popular I went there a few months ago, Wolchulsan NP is pretty awesome also in the deep south, small but imposing and some beautiful hikes in there.

Buy a ticket in advance, and if you are going by road, expect huge traffic jams. I know someone who once took 17 hours to drive from Seoul to Busan during Chuseok.