Seollal (설날), or Korean New Year, is the first day of the Lunar Calendar and one of the two most important traditional Korean holidays (the other is Chuseok).
Seollal normally falls on the same day as Chinese New Year and shared similar traditional celebrations, such as paying tribute to their ancestors/elders, dressing in traditional costumes (and/or new clothes) and feast on traditional food etc.
On the morning of Seollal, Koreans dressed in their Seolbim (new clothes prepared for Seollal), often in Hanboks (pic). Family members then gather to perform ancestral rites to pay their respects as well as to pray for a prosperous year ahead.
After the rituals, they eat Tteokguk (rice-cake soup); according to tradition, eating Tteokguk on Seollal adds one year to their age. After the meal, the younger generations pay respects to the elders in their family by bowing to them, and the elders offer their blessing and Sebae-don (New Year’s money) in return.
Traditional folk games are often played during the festive season… such as Yutnori (a board game played by tossing sticks), Paengichigi (top spinning) and Neolttwigi (standing, high-jump seesaw) etc. Many Korean folks would also consult fortune-tellers about their fortune in the coming year.
Read more about Seollal celebrations on Korea.net and Koreatimes.