Staying in Myeongdong, Seoul 3 days with 2 kids, single parent

Hi all, I'll be visiting Seoul in a couple days with 2 toddlers (7+). My wife is Korean and arrives 3 days later due to work.

I will be solo parenting who speaks 0 korean and am trying to figure out what to do with my kids before my wife arrives. I dont want to do the big touristy stuff because I want to do that as a family unit. Are there any suggestions in terms of activities or sights that are kid friendly for Thursday, friday and saturday?

Im staying at Le Meridien in terms of location so I think im walking distance to most things.