Sobaeksan Mountain (소백산) is renowned for its natural splendor and mystery, standing tall in the middle of the Korean peninsula, and offering several magnificent peaks such as Hyeongjebong, Sinseonbong, Gukmangbong, Birobong and Yeonhwabong. Its captivating seasonal beauty (royal azalea in spring, wildflowers in summer, autumn foliage in fall, snowscape in winter) attracts visitors year-round. The open grass field on Birobong Peak (비로봉, 1,439m in elevation) is reminiscent of a scene from the Swiss Alps. The National Planetarium located upon Yeonhwabong Peak (1,349m in elevation) is the historic cradle of Korean astronomy. The nationwide Sobaeksan Royal Azalea Festival is held near Danyang-gun in early June every year.