The Seoul Museum of History Children's Museum recommends free online reservations for at least two people and up to five tickets per booking. Book or cancel by the day before your visit. If you miss the assigned start time, entry may begin after a 15-minute wait, but the reservation is automatically canceled after 20 minutes. Uncanceled no-shows can result in a 60-day booking restriction. Only ten walk-in places including adults and children are offered first-come starting 30 minutes before each session. Children require adult guardians, and adults cannot enter alone.