To visit 13 of the 18 serial components it took 3 visits to Korea!
(2008, 2011, 2016) Granted this TWHS and then WHS was not a primary destination, but unless you want to spend the better part of a week to visit 10 or more tomb clusters, and not much else, I would not recommend it. Realistically, any dedicated traveller could comfortably visit 2-3 tomb clusters a day. While I love trying to complete components of a serial nomination, its best to spread out the visits to not undermine the enjoyment.