Every year, on April 8th (lunar calendar) the city of Seoul celebrates Buddha's Birthday with the Lotus Lantern Festival. Lotus shaped lanterns are hung around Seoul leading up to the festival, particularly at a couple of the larger Buddhist temples: Bongeunsa (pictured) and Joggyesa. Even if you're not Buddhist, you can enjoy seeing all the decorations and other festivities such as a parade and performances. Be mindful of the parade though, as it can cause some traffic.