Yi Peng, often confused with the nationwide Loy Krathong festival, is the distinct and magical lantern festival celebrated predominantly in the northern regions of Thailand, particularly in Chiang Mai. Taking place concurrently with Loy Krathong (usually on the full moon of the twelfth lunar month, typically in November), Yi Peng transforms the night sky into a breathtaking spectacle of thousands of softly glowing, soaring lanterns.The name "Yi Peng" itself is derived from the Northern Thai dialect, where Yi means "two" and Peng means "full moon day," signifying the full moon of the second month of the Lanna calendar. This festival is a celebration of the ancient Lanna Kingdom, and its primary tradition involves the launch of the iconic khom loi (or khom fai), large paper lanterns made from thin bamboo frames and covered with delicate rice paper.The act of releasing the lanterns is deeply spiritual and symbolic. Participants light a small candle or fuel cell inside the base of the lantern, allowing the heated air to inflate the paper canopy. As the khom loi gracefully lifts into the night, it is believed to carry away the flier's misfortunes, bad luck, and worries from the previous year. The rising lantern is also seen as a way to pay homage to Phra That Chulamani, a celestial chedi (stupa) said to hold a relic of the Buddha's hair, and to make merit for the year ahead.The sight of thousands of these golden orbs ascending silently into the vast, dark expanse is an overwhelmingly peaceful and beautiful experience. Beyond the main launching events, the festival is also marked by smaller lanterns hung around temples and homes, colorful parades, and the simultaneous floating of krathongs (small decorated rafts) on the water, cementing Yi Peng's status as one of Thailand's most visually stunning and spiritually moving celebrations.